Key Words
Intra-aortic balloon pump - Entrapment - Aorta
Introduction
The intra-aortic balloon pump (IABP) provides mechanical hemodynamic support and improves
coronary perfusion, making it a valuable tool for cardiac surgeons in the postoperative
setting[1]. However, it is also associated with a high complication rate of up to 30%, with
patients experiencing fever, thrombocytopenia, limb ischemia, bleeding, and entrapment[2]. IABP entrapment is a rare but major complication with a described incidence of
less than 2%[3]
[4]
[5]. In this report, we present the case of a patient with a ruptured and entrapped
IABP that required emergent removal and subsequent repair of the iliofemoral arteries
and review the literature on the presentation and management of IABP rupture and entrapment.
Case Presentation
An 82-year-old female presented to the Royal Melbourne Hospital with symptomatic severe
aortic calcific stenosis (aortic valve area 0.5 cm2), moderate-to-severe tricuspid regurgitation, and severe pulmonary hypertension.
She underwent an elective bioprosthetic aortic valve replacement and tricuspid valve
repair with an annuloplasty ring. The operation was successful and uncomplicated.
Two days after the procedure, the patient’s cardiac index dropped, and she required
increasing doses of inotropes. She was subsequently returned to surgery for suspected
cardiac tamponade, but this was not found on re-exploration, and an IABP was inserted
for hemodynamic support. One day after placement, the IABP was advanced a further
4 cm, and a correct position was confirmed on chest X-ray. It was noted two days post
insertion that the IABP had poor augmentation and therefore the IABP was advanced
another 5 cm restoring good augmentation. Blood was noticed in the tubing the next
day, and no more deviation in balloon inflation/waveform was noted. An attempt to
remove the IABP in the intensive care unit (ICU) was unsuccessful as resistance was
felt, and the IABP was thought to have lodged into the right common femoral artery.
The patient developed an ischemic right limb, which necessitated urgent surgical removal
of the IABP via an extra-peritoneal approach to the right iliac vessels after failed
removal through an oblique groin incision and cut into the common femoral artery.
The IABP had ruptured and thrombosed ([Figure 1]), causing entrapment and dissection of the right external iliac artery, which was
repaired by an interposition expanded polytetrafluoroethylene graft ([Figure 2]). The patient’s recovery following revision surgery was uneventful. Her cardiogenic
shock resolved, and after a prolonged stay in ICU for line sepsis and acute kidney
injury, the patient was discharged to cardiac rehabilitation and is currently still
alive.
Figure 1. Extracted intra-aortic balloon pump with a thrombus in the balloon tip.
Figure 2. Schematic drawing of intraoperative findings. Entrapped balloon pump in right external
iliac artery with delaminated common iliac artery (Panel A). Final repair with iliofemoral bypass interposition graft (Panel B).
Discussion
The use of an IABP has a significant complication rate of 20–30%, with fever and thrombocytopenia
being the most common[2]. The main major complications are acute limb ischemia, bleeding, aortoiliac injury,
aortic dissection, and thromboembolic phenomena, with entrapment considered a rare
complication[2]. Large cohort studies and registries have reported that the incidence of IABP rupture
and entrapment ranges within 1–1.7%[3]
[4]
[5].
IABP rupture is probably caused by rubbing of an abrasive aortic plaque against the
smooth surface of the balloon. Tears in the balloon have also been attributed to design
and manufacturing issues. Entrapment is subsequently caused by the development of
a bulky thrombus load inside the ruptured balloon.
Early identification of balloon rupture is pivotal in preventing IABP entrapment postrupture.
However, rupture may be hard to detect because often the leakage alarm fails due to
tamponade of the ruptured balloon with thrombus, mimicking a functioning balloon[1]. In a cohort study of 2,803 patients, alarms for gas leakage were insensitive for
rupture and were only effective in 29% of patients. Device error indicators, loss
of augmentation, frequent IABP filling, and blood in the safety chamber or tubing
are warning signs of rupture. Blood inside the catheter shaft was the indicator that
raised the suspicion of IABP rupture in 80% of patients[4]. Clinically, the presence of limb ischemia and ineffective hemodynamic support should
always raise the suspicion of rupture.
Only a handful of case reports have been published on the management of IABP rupture
and entrapment in the iliac system. Naturally, the goal of management should be safe
removal of the IABP. However, there have been documented cases of forceful extraction
resulting in unintentional damage to the external iliac and common femoral arteries[6]
[7]. Complications arising from such methods have resulted in acute limb ischemia, the
need for bypass surgery, and even death[6].
Both percutaneous and open approaches have been described for the safe removal of
the ruptured IABP. Local delivery of streptokinase, urokinase, heparin, or tissue
plasminogen activator into the gas-driven lumen of the balloon catheter has dissolved
the clot within the IABP lumen, enabling a normal percutaneous extraction of the balloon
catheter without surgery[6]
[8]. However, an open surgical approach has been the extraction modality of choice in
recent times[6]
[8]
[9]. Open inguinal access to the femoral and/or iliac vessels is the mainstay approach
for removal of the entrapped IABP due to the ease of access and possibility for safe
extraction under direct vision, although successful trans- and retroperitoneal approaches
have also been described[7]
[10]. As in our case, IABP rupture and entrapment often causes substantial damage to
the iliofemoral arteries, necessitating vascular repair by endarterectomy, patch closure,
or even bypass graft and resulting in significant morbidity for the patient.
In conclusion, balloon rupture and entrapment is a rare complication in patients treated
with an IABP, and it is often difficult to detect. Management should be aimed at early
rupture detection with a low threshold to remove the IABP before entrapment can occur.
In case of IABP entrapment, either percutaneous removal in conjunction with local
or systemic thrombolysis or surgical extraction should be performed, followed by repair
of the damaged iliofemoral arteries.
