Page 204 - Read Online

life-threatening complication of thermal ablation Regardless of the exact mechanism responsible for
treatments. To date, 4 cases of cardiac tamponade hemorrhagic cardiac tamponade in our patient, this case
have been reported in literature as a complication report highlights some issues that should be considered
of percutaneous thermal ablation. [6-8] In all cases, in future similar cases. First, in all four cases previously
the complication occurred after RFA of liver nodules reported in literature as well as in our patient, such a life-
performed by using expandable radiofrequency needles. threatening complication occurred with tumors located
The authors hypothesized two possible explanations for in segment II of the liver. [6-8] Although cardiac tamponade
the occurrence of cardiac tamponade. [6-8] First, the exact is an extremely infrequent complication of thermal
position of expandable RFA needles is more complicated ablation and is more likely to occur when expandable
to track at any time than that of the non-expandable RFA needles are used, [6-8] our experience shows that it
RFA probes, MWA antennas, or LTA fibers. Therefore, a may also occur with other theoretically safer techniques,
RFA hook could have inadvertently been placed in the such as LTA. Therefore, tumor location in segment II must
diaphragm or in the pericardium, causing direct injury to be considered a major risk factor for cardiac tamponade
these structures. Indeed, in 2 cases the presence of a RFA during ablation procedures regardless of technique used,
[6]
hook in the pericardial fat was documented by computed and according to Moumouh et al., we wonder: “was
[8]
tomography. Secondly, in some unclear circumstances, percutaneous thermal ablation the best therapeutic option
the distribution of heat in vivo may be unpredictable, and in this case?” A careful risk/benefit analysis must be made
the pericardium can become injured by heat conduction. ideally by the multidisciplinary team before treating
Indeed, tissues exposed to elevated temperature may react tumors located in segment II. Surgical resection or thermal
with an inflammatory or hemorrhagic response, and such ablation with open or laparoscopic approach could be
an injury has been observed in other viscera such as the gall considered, as they may be easier for isolating the lesion
bladder or colon. [11] from adjacent critical structures and potentially provide
better control of bleeding. [11] However, these approaches
Although LTA has been less investigated than the other are more invasive and not always simple, and the risk of
ablation techniques, it seems to have the same efficacy complications due to an open or laparoscopic approach
and safety profile as RFA. By using one to four fibers should be weighed against the risk of cardiac tamponade.
according to the tumor size, the reported complete In addition, alternative locoregional treatments such
response rates range from 82% to 97% (hazard ratio). as transarterial chemoembolization or stereotactic
Mortality rate is < 1%, and major complication rate radiotherapy, or non thermal ablation techniques such
ranges from 1% to 3.5%. [5] as ethanol injection in presence of primary liver tumors
should be considered.
To the best of our knowledge, this is the first case of
cardiac tamponade following LTA reported in literature. Second, early detection of cardiac tamponade is pivotal
LTA was preferred to other ablation techniques for lesions to minimize its clinical magnitude, and US scans of the
with small diameters, and those with difficult location. pericardial space should be promptly performed when
The procedure was performed under US-guidance, which blood pressure suddenly drops during thermal ablation
enables one to check the position of the needle in real- of nodules located in segment II. Likewise, careful
time, minimizing the risk of incorrect placement and consideration should be given to the location where
direct injury to the diaphragm. Moreover, unlike RFA and the procedure is performed, in order to ensure rapid
MWA where the ablation device is advanced through the availability of emergency personnel and emergency
entire lesion, using LTA technique the advancement of resuscitation equipment to properly manage major
the needle tip was stopped 1 cm from the deepest part complications when they occur.
of the tumor, and just the very flexible, flat-tip fibers
were placed close to the diaphragm, making direct injury Finally, the treatment planning of a nodule in segment II
to the diaphragm or pericardium by the needle tip very should include the presence, or at least the immediate
unlikely. Furthermore, no damage to diaphragmatic availability, of an interventional radiologist or cardiologist
arteries or left hepatic arterial vessels was documented very experienced in the placement of pericardial drains.
by abdominal artery angiography. For all these reasons,
even though we cannot exclude with absolute certainty Financial support and sponsorship
direct damage of pericardium, we believe that the most Nil.
likely explanation for cardiac tamponade in our patient
was unpredictable heat diffusion that caused indirect Conflicts of interest
thermal injury to the pericardium with hemorrhagic There are no conflicts of interest.
reaction. Indeed, CEUS performed a few days after LTA
documented successful ablation with a coagulation REFERENCES
area 24 mm × 22 mm in size as expected, indirectly
confirming that both needles and laser fibers had been 1. Lahat E, Eshkenazy R, Zendel A, Zakai BB, Maor M, Dreznik
correctly placed into the tumor. Y, Ariche A. Complications after percutaneous ablation of liver

Hepatoma Research | Volume 2 | July 1, 2016 195