To the Editor:
Since its introduction by Schnitzbauer et al
1
in 2012, associating liver partition and portal vein ligation for staged hepatectomy
(ALPPS) became a promising strategy for patients with insufficient future liver remnant
(FLR). Despite the efficacy of ALPPS in triggering rapid hypertrophy of FLR, high
incidence of postoperative morbidity and mortality poses a major drawback, especially
for those hepatocellular carcinomas (HCCs) with liver cirrhosis. We read the paper
with great interest by Gringeri et al
2
describing a new minimally invasive laparoscopic microwave ablation and portal vein
ligation for staged hepatectomy (LAPS) on the future transection plane, resulting
in a satisfactory hypertrophy of FLR and an easier second step in HCC. Since anatomic
hepatectomy (right/extended right hemihepatectomy or right trisectionectomy) was usually
applied for huge HCC, with a relatively lower hypertrophic rate as 48.7% compared
with colorectal liver metastasis (CRLM)
3
in ALPPS or modified ALPPS, and considering the enormous stress upon patients enduring
2 laparotomies, we present a novel minimally invasive approach implementing percutaneous
microwave ablation liver partition and portal vein embolization (PALPP) instead of
the first step of ALPPS for rapid liver regeneration.
A 43-year-old man (weight 67 kg; height 170 cm; body mass index 23.3 kg/m2) was admitted
with a liver mass discovered incidentally by ultrasound. Medical history was significant
for 15 years of hepatitis B virus infection. Serum α-fetoprotein (AFP) was 885.2 ng/L.
Dynamic enhanced computed tomography (CT) imaging revealed multiple masses in the
right lobe, a 2.0 cm × 1.5 cm intrahepatic metastasis in segment III (sIII), and a
1.5 cm × 1.5 cm intrahepatic metastasis in segment IV (sIV) (Fig. 1A, B). The patient's
Stevenson body surface area was 1.74 m2, with standard liver volume (SLV) of 1231.2 mL
in Urata format. Liver volumetric CT scan measured the FLR at 355.6 mL, which was
accounting for 28.9% of the total SLV. Since the inadequate FLR could not allow for
a 1-step right trisectionectomy in combination with tumor resection in sIII, PALPP
was designed to meet the challenges of this complicated case.
FIGURE 1
A, Computed tomography (CT) scan showing a sizable mass (arrow) in the right lobe
of the liver. B, A 2.0 cm × 1.5 cm satellite lesion (arrow) situated in sIII. C, Occlusion
of the right portal vein and the transection plane (arrow) after PVE and PMA. D, PMA
transection plane (A); parenchymal transection line (B), as planned lateral to PMA
plane. E, PMA transection plane (arrow) with minimal adhesion found intraoperatively.
F, Completed right trisectionectomy and excision of the sIII lesion. G, CT scan confirming
FLR hypertrophy on postoperative day 7. PVE indicates portal vein embolization.
First, under ultrasonographic guidance, percutaneous microwave ablation (PMA) was
applied every 3 cm along the transection plane until formation of a necrotic groove
from the inferior liver to the suprahepatic veins. The PMA antenna was positioned
on the right side of the transection plane at a power of 60 W set as a 3-minute ablation
cycle. The tumor in sIV was ablated simultaneously. The tumor in the sIII was preoperatively
controlled by dehydrated alcohol. The patient experienced a 2-day fervescence with
peak body temperature measured at 38.9°C. Liver function was suboptimal on day 1 post-PMA,
returning to normal range on day 2.
Three days after PMA, portal vein embolization (PVE) was performed. Coil was placed
into the trunk of the right portal vein, followed by injection of mixed embolic agent
(total volume of 0.2 mL, 2 mL medical glue, and 2 mL Lipiodol) into the distal right
portal vein (Fig. 1C). The patient sustained a mild fever after PVE, with liver function
maintained within normal range. Enhanced CT imaging obtained 10 days after PVE revealed
a satisfactory hypertrophy of FLR with volume of 502.1 mL, accounting for 40.8% of
the SLV and amplitude increase of 41.2% (Fig. 1D).
A well-planned right trisectionectomy in conjunction with sIII tumor resection was
performed on day 14 after PVE. Minimal adhesion was noted along the PMA line (Fig.
1E). Anterior approach was taken during right trisectionectomy. The transection line
was made at the left side of the PMA plane (1.5 cm wide). The tumor previously saturated
with dehydrated alcohol in sIII was then removed (Fig. 1F). The total operation time
was 300 minutes. Postoperative course was significant for mild ascites requiring medical
treatment (Clavien-Dindo grade II). The patient remained free of fever, bile leak,
or liver dysfunction. A 16.1% gain in FLR volume was observed on CT scan performed
on postoperative day (POD) 7, with total volume of 583 mL (Fig. 1G). The patient was
discharged on POD 15.
Since high morbidity (mean 44%, grade ≥3b) and 3-month mortality rate (mean 11%) remain
serious drawbacks of ALPPS, specialists continue to modify surgical methodology, yielding
novel techniques such as anterior approach in ALPPS,
3
complete laparoscopic ALPPS,
4
the LAPS procedure,
2
RALPP,
5
and monosegment ALPPS.
6
Unfortunately, all of these interventions consist of 2 surgical procedures and impose
enormous physical and psychological stress upon patients enduring 2 laparotomies.
We introduce PALPP procedure as an effort to reduce the morbidity and mortality associated
with large HCC tumors. We present the first case to our knowledge reporting a new
minimally invasive procedure for treatment of primary liver carcinoma with insufficient
FLR. In our center, 3 cases of HCC and 1 case of perihilar cholangiocarcinoma have
been performed using this new minimally invasive approach with optimistic outcome
(data were not shown).
Compared with the dual-operation paradigm of classic and modified ALPPS, the PALPP
offers alleviated technical burden attributable to less adhesion after PMA. PMA and
PVE are “in situ” procedures; tumor spread caused by direct PVL and parenchymal involvement
in ALPPS could thus be mitigated by the less invasive technique. Moreover, the application
of PMA in combination with PVE allows a rapid increase of FLR in a shorter time than
traditional PVE/PVL. Inflammatory cytokines such as interleukin-6, tumor necrosis
factor-α, and the STAT3 pathway induced by PMA play an important role in the remnant
hypertrophy,
2,7
and would elicit effects even if the parenchyma were not completely spit by PMA, consistent
with prior evidence of successful “partial ALPPS.”
8
Finally, in situ splitting line made at the left side of the PMA plane shows microscopically
coagulative necrosis, thus effectively reducing intraoperative blood loss and risk
of postoperative bleeding and bile leak. The outcome of hypertrophic rate in our case
was 41.2%, with a satisfactory liver function postoperatively, which is similar to
the results as described in HCC.
3
Promising as it seems to be, this technique, as we conservatively suggest, should
be applied on those indicated for right/extended right hemihepatectomy or right trisectionectomy
in primary liver carcinoma and colorectal liver metastases,
4
with the insufficient FLR being the major concern. Fortunately, more than 95% of the
ALPPS procedures for HCC were reported as right hemihepatectomy or right trisectionectomy.
Chan et al
3
reported 17 cases of ALPPS for HCC, in which 14 cases were right hemihepatectomy and
3 were right trisectionectomy. A series of 202 ALPPS was analyzed by Schadde et al
which revealed that 141 cases (70%) were CRLM, in which right hemihepatectomy was
performed in 106 cases (52%) and right trisectionectomy in 86 cases (43%).
9
Whereas for those extensive bilobar colorectal liver metastases, a monosegment ALPPS
was suggested.
6
In summary, we provide a novel surgical approach to cases of locally advanced liver
tumors. We think that PALPP could be a more minimal technique alternative to the first
step of ALPPS, and associated with low morbidity and mortality rates for huge primary
liver carcinoma in which an anatomic hepatectomy was needed. Further application and
evaluation of PALPP is necessary to demonstrate its safety and efficacy in selected
cases.