Abstract
Abstract
Background:
The surgical therapy of choice for hepatocellular carcinoma (HCC) is liver transplantation (LT) or hepatic resection, although only a small percentage of patients can undergo these procedures. Microwave thermal ablation (MWTA) can be an effective alternative treatment for HCC that complicates a cirrhotic liver disease, either as a final procedure or for downstaging patients on the waiting list for LT, or in combination with resective surgery to achieve oncological radicality.
Objective:
The purpose of this retrospective study was to evaluate experience with the laparoscopic approach of MWTA at our center.
Materials and Methods:
In a cohort of 35 consecutive patients undergoing MWTA with laparoscopic approach between January, 2013 and May, 2016, we reviewed the demographic data, the Barcelona clinic liver cancer stage, the severity of cirrhotic liver disease, the size of the ablated lesion, the duration of the procedure, and complications occurring within 90 days of surgery.
Results:
MWTA was performed by applying one to three hepatic parenchymal insertions (mean 1.8) per patient. The mean duration of surgery was 163 ± 18 minutes. There was no blood loss in any of the procedures. Complete necrosis on CT scan was achieved in 26/35 patients (75%). The mean hospital stay was 4.6 (range 2–7) days; major complications were postablation syndrome in 2/35 (5.7%), peritoneal fluid in 4/35 (11.4%), and transient jaundice in 1/35 (2.8%) patients. There was no mortality.
Conclusions:
Laparoscopic MTWA is a safe and effective treatment for unresectable HCC and when a percutaneous procedure is not feasible.
Introduction
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Laparoscopic surgery is one the mayor advancements in medicine in the past three decades, and has rapidly replaced the open approach in many surgical fields. For portal hypertension, mini-invasive approaches are particularly useful in reducing ascites, blood loss, postoperative pain, and postoperative morbidity, and lead to faster recovery than conventional open surgery. 8
In light of these facts, we postulated that the possibility to perform laparoscopic microwave thermal ablation (LMWTA) under intraoperative laparoscopic ultrasound guide, for the treatment of HCCs on chronic liver disease, would have positively impacted the outcome of these patients. To explore this hypothesis, we reviewed our approach to LMWTA over the past 3 years since we have introduced this particular technique, looking at our single-center retrospective series.
Materials and Methods
From January, 2013, to May, 2016, a cohort of consecutive patients underwent LMWTA for HCC in a single tertiary center. All of the procedures were performed by one team of surgeons.
Patients identified as candidates for LMWTA were those judged ineligible for LR and percutaneous approach. The tumors were all <5 cm in diameter, and liver function did not exceed class B of the Barcelona Clinic Liver Cancer (BCLC) score system.
The study was approved by our Institutional Research Board, and informed consent for all surgical procedures was obtained from each patient in this retrospective study.
The patients returned for follow-up evaluation every 2 months after the operation. Patient data were collected and analyzed with SPSS software (SPSS, Chicago, IL).
Patient and trocar position
When the MWTA approach was planned for left lateral segments or anterior segments, the patient was placed in supine position with the 30-degree reverse Trendelenburg position, and the surgeon positioned between the patient's legs. An open approach with a Hasson trocar was used above the umbilicus unless a patent umbilical vein was detected preoperatively.
Carbon dioxide pneumoperitoneum was created and maintained between 10 and 12 mm Hg. Subsequently, one 10–12 mm trocar was advanced in the same site, and the liver was visually assessed using a 35-degree optical device. The infraumbilical trocar was utilized for the scope, and the camera holder was placed between the patient's legs.
Thermal ablation of HCC located in the posterior segments was performed with the patient in left lateral recumbent position. The right-sided trocars were for the surgeon and left-sided trocars for the assistant.
The port positions were associated according to the HCC location: two additional trocars (10–12 or 5 mm) were inserted in the upper abdominal quadrants. Intraoperative laparoscopic ultrasound guidance (Pro Focus UltraView 800 Ultrasound System; BK Medical, Herlev, Denmark) was performed on each patient to detect the exact HCC position, and Doppler examinations were done to provide a better definition of anatomic characteristics, for example, HCC lesions near the main intrahepatic vessels, gallbladder, or bile ducts.
The round and falciform ligaments were divided with harmonic scissors when HCC was located close to the fourth segment, and portal hypertension was not severe. The left triangular ligament was dissected only in cases of neoplastic involvement of the second and/or third segments. The lesser omentum was opened through the pars flaccida for HCC located in the first segment.
MWTA system
MWTA was performed with a commercially available system with a 2.45 MHz generator and a maximum power of 100 W of energy (AMICA-GEN; HS Hospital Service S.p.A., Aprilia, Italy). A single 14- or 16-gauge transcutaneous, water-cooled antenna (AMICA PROBE; HS Hospital Service S.p.A., Aprilia, Italy) was placed under real-time ultrasound guidance using a laparoscopic transducer (4-Way Laparoscopic 8666-RF; BK Medical, Herlev, Denmark).
The MWTA system is composed of the following:
(1) A programmable energy source, designed to generate the power required and monitor energy delivery to the patient.9,10 (2) An interstitial antenna, equipped with a coaxial semirigid cable capable of emitting MW radiation from its exposed—but not covered by the outer conductor—distal end, inserted in a needle-like device,
3
and a power transmission line that connects the output ports' energy source to the antennas.
Results
Thirty-five patients with HCC were included in this study. The male-to-female ratio was 2.9:1, and the mean age of the patients was 64 years (range 48–78 years) (Table 1).
ASA, American Society of Anesthesiologists Classification System; BCLC, Barcelona clinic liver cancer; BMI, body mass index; CTP, Child-Turcotte-Pugh score; MELD, Model for End-Stage Liver Disease score; LR, liver resection; SD, standard deviation.
The number of operations increased annually: 1 in 2013, 8 in 2014, 18 in 2015, and 8 cases in the first 5 months of 2016. LMWTA was completed in all patients, with no conversion rate.
One patient, Child-Pugh C stage, with a lesion proximal to the gallbladder, underwent gallbladder detachment from the gallbladder bed, but no cholecystectomy due to the potentially high risk of complications. The mean diameter of the tumors was 2.8 ± 1.2 cm. Using the BCLC staging system, 22.8% had early stage disease (A) and 77.2% had intermediate-stage disease (B). The main cause of liver cirrhosis was hepatitis C virus infection in 57.2% of cases. The HCC nodules were treated for 8–10 minutes at 40–80 W to ensure appropriate coagulation necrosis of the targeted cancer and a margin of 1 cm of tumor-free parenchyma (Fig. 1).
Hepatic segmental distribution of hepatocellular carcinoma nodules treated with laparoscopic microwave thermal ablation in our series.
LMWTA was performed by applying one to three hepatic parenchymal insertions (mean 1.8) per patient. The mean duration of surgery was 170 ± 76.7 minutes. There was no blood loss in any of the procedures. In one case, we used real-time navigation with the CASone Liver Navigation System (CAScination AG, Switzerland) to better target a deep lesion located in the eighth segment. Complete necrosis on postoperative CT scan was achieved in 26/35 patients (75%). The mean hospital stay was 4.6 (range 2–7) days. Major complications were postablation syndrome in 2/35 (5.7%), peritoneal fluid in 4/35 (11.4%), and transient jaundice in 1/35 (2.8%) patients. There was no mortality. The follow-up period was 14.1 ± 7.5 months. The disease-free survival rates in this study were 77.2% at 1 year and 66.1% at 2 years. The mean disease-free survival time was 10 ± 5.68 months (range 4–20 months). Overall survival rates were 85.7% at 1 year and 82.8% at 2 years. Mean overall survival was 11 ± 6.16 months (range 5–24 months).
Discussion
Thermal ablation therapies are a good alternative option for the treatment of HCC because of their reduced invasiveness, tolerability profile, and safety. The laparoscopic approach can guarantee efficacy in controlling local bleeding and can be limitlessly repeated. At present, thermal ablation is used in different settings of HCC therapy, such as definitive therapy in patients who are ineligible for LR or LT, or in downstaging patients before LT.11,12
Different energy sources are currently available. The purpose of the interstitial thermal ablation treatments is to destroy solid HCC by raising their temperature above a lethal threshold. 13
Nine microwave systems have been documented and reported, and differences are considerable in terms of frequency, power supplied, probe diameter, probe-cooling system availability, and device miniaturization to decrease MWTA reflection.9,10,14,15 The standardization of clinical indications and device decision criteria for reporting MWTA outcomes is becoming increasingly necessary to compare the different methods.
The laparoscopic approach can facilitate the treatment of several lesions in a single session, as recently reported by Cillo et al. in a prospective cohort study. They described the treatment of 50 HCCs in 42 patients with LMWTA and obtained a complete ablation rate of 100% in patients with HCC <3 cm in diameter and of 80% in patients with HCCs ≥3.0 cm. The 2-year survival rate was 81%, and the 2-year recurrence rate was 55%, with no perioperative mortality and a median postoperative hospital stay of 3 days. 16
MWTA under computer-assisted navigation (CASone Liver Navigation System) is a valid and promising tool for approaching deep lesions close to major intrahepatic vessels or larger bile ducts. Stereotactic instrument guidance based on previous 3D image data and the real-time measurements of the instruments were recently described by Engstrand et al.17–21
Over the past 3 years with the introduction of LMWTA, we changed our attitude for the treatment of nonresectable HCCs, indeed we performed less intraarterial chemoembolization and more LMWTA. Despite the excellent survival rate achieved by our group after TACE that was 76.2%, 56.2%, and 47.7% at 1, 2, and 3 years, respectively, 22 our preference shifted toward LMWTA when feasible because of the flexibility of this last procedure that allowed successful mini-invasive treatment of multiple nodules at the same time.
Conclusions
Our study is subjected to a number of limitations, the most important of which is its retrospective design, with all of the inherent limitations of retrospective studies. The relatively small group of patients also limited the number of variables that could be simultaneously investigated with multiple linear regression analysis. In addition, this was a single-center study and was done in a small, highly specialized, and dedicated transplant hospital, with experience in Liver surgery, which means that the associations we found are likely not generalizable to larger, more heterogeneous settings. It is our hope that future, prospective, observational, and preferably multicenter studies will shed further light on the use of LMWTA. However, our experience is a successful example of safe and effective treatment for unresectable HCC surgery when a percutaneous procedure is not feasible.
Footnotes
Disclosure Statement
This article has not been published and is not under consideration elsewhere. We declare that all authors are in agreement on the content of the article and have no potential conflicts of interest. We have nothing to disclose regarding sources of support in the form of grants, equipment, and/or pharmaceuticals. The authors of this article have no conflicts of interest, as described by this journal, to disclose.