Treatment of liver colorectal metastases: role of laparoscopy, radiofrequency ablation, and microwave coagulation

Predicting the coagulation volume induced by microwave ablation of hepatocellular carcinoma: the role of deposited energy, ex-vivo bovine liver charts and central hyperdense area on post-treatment CT

PURPOSE

To study the correlation between the overall coagulation zone (A) attained in percutaneous microwave ablation (MWA) of hepatocellular carcinomas (HCC) and: (1) the hyperdense zone (C) visible in the central part of zone A on post-treatment unenhanced CT scans; (2) the deposited energy; (3) the coagulation zones observed on ex-vivo bovine liver.

MATERIALS AND METHODS

The post-procedural computed tomography (CT) scans of HCCs treated with a single energy deployment through the same 2450 MHz MWA system were retrospectively analyzed, retrieving the dimensions of A and C zones and the deposited energy (E). Ex-vivo bovine liver MWA with the same system were performed and analyzed to determine the same quantities by gross-pathologic examination and CT imaging.

RESULTS

A total of 101 HCC treatments were analyzed. The average coagulation volumes increased linearly with deposited energy (1.11 cc/kJ, R² = 0.90, 4.2 kJ ≤ E ≤ 48 kJ), similarly to ex-vivo findings (1.38 cc/kJ, R² =0.97, 7.2 kJ ≤ E ≤ 144 kJ). The long axis (L) and short axis (D) of zones A and C held a fairly constant ratio both in-vivo (L_C/L_A=0.43 ± 0.13; D_C/D_A=0.42 ± 0.10) and ex-vivo (L_C/L_A = 0.49 ± 0.07; D_C/D_A = 0.28 ± 0.06).

CONCLUSIONS

The average dimensions of the ablation zone induced by the considered system on HCC increase linearly with the deposited energy and are fairly well predicted by the corresponding ex-vivo dimensions. The ratio between each linear dimension of A and C zones was found to be roughly constant over a large deposited energy span, both ex-vivo and in-vivo.

The local efficacy and influencing factors of ultrasound-guided percutaneous microwave ablation in colorectal liver metastases: a review of a 4-year experience at a single center

PURPOSE

To investigate the clinical effectiveness and safety of ultrasound (US)-guided percutaneous microwave ablation (MWA) for colorectal liver metastasis (CRLM) and evaluate the influencing factors of local efficacy.

METHODS

From January 2013 to January 2017, 137 CRLM patients accepting US-guided percutaneous MWA were included. The 2450-MHz microwave ablation system and a cooled-shaft antenna were used. All patients were regularly followed up for at least 6 months. Technical success, complete ablation, local tumor progression (LTP), complications and side effects were assessed. Logistic regression analysis was used to identify the independent prognostic factors for LTP.

RESULTS

In total, 411 lesions (mean diameter 15.4 ± 7.2 mm, range 5-67 mm) were treated. Complete ablation was achieved in 99.27% (408/411) of lesions and 97.81% (134/137) of patients. LTP occurred in 5.35% (22/411) of lesions and 16.06% (22/137) of patients. LTP was more likely to occur in lesions larger than 3 cm in diameter (OR: 14.71; p < .001; 95% CI: 3.7 3-57.92), near a large vascular structure (OR: 7.04; p < .001; 95% CI: 2.41-20.60), near the diaphragm (OR: 4.02; p = .049; 95% CI: 1.05-16.11) and in patients with no response to chemotherapy before MWA (OR: 3.25; p = .032; 95% CI: 1.14-15.30). MWA was well tolerated, with a major complication rate of 3.65%, a minor complication rate of 8.03% and a mortality rate of 0%. Fever and pain were the most common side effects after MWA.

CONCLUSIONS

US-guided percutaneous MWA of CRLM is a safe and effective method that is expected to become a routine treatment for local tumor control of CRLM.

Patient selection for the surgical treatment of resectable colorectal liver metastases

Advances in surgery and chemotherapy regimens have increased the long-term survival of patients with colorectal liver metastases (CRLM). Although liver resection remains an essential part of any curative strategy for resectable CRLM, chemotherapy regimens have also improved the long-term outcomes. However, the optimal timing for chemotherapy regimens remains unclear. Thus, this review addressed key points to aid the decision-making process regarding the timing of chemotherapy and surgery for patients with resectable CRLM. J. Surg. Oncol. 2017;115:213-220. © 2016 Wiley Periodicals, Inc.

Parenchymal-sparing liver surgery in patients with colorectal carcinoma liver metastases

Liver resection is the treatment of choice for patients with colorectal liver metastases (CLM). However, major resections are often required to achieve R0 resection, which are associated with substantial rates of morbidity and mortality. Maximizing the amount of residual liver gained increasing significance in modern liver surgery due to the high incidence of chemotherapy-associated parenchymal injury. This fact, along with the progressive expansion of resectability criteria, has led to the development of a surgical philosophy known as "parenchymal-sparing liver surgery" (PSLS). This philosophy includes a variety of resection strategies, either performed alone or in combination with ablative therapies. A profound knowledge of liver anatomy and expert intraoperative ultrasound skills are required to perform PSLS appropriately and safely. There is a clear trend toward PSLS in hepatobiliary centers worldwide as current evidence indicates that tumor biology is the most important predictor of intrahepatic recurrence and survival, rather than the extent of a negative resection margin. Tumor removal avoiding the unnecessary sacrifice of functional parenchyma has been associated with less surgical stress, fewer postoperative complications, uncompromised cancer-related outcomes and higher feasibility of future resections. The increasing evidence supporting PSLS prompts its consideration as the gold-standard surgical approach for CLM.

Clinical practice guidelines for the management of metastatic colorectal cancer: a consensus statement of the Hellenic Society of Medical Oncologists (HeSMO)

There is discrepancy and failure to adhere to current international guidelines for the management of metastatic colorectal cancer (CRC) in hospitals in Greece and Cyprus. The aim of the present document is to provide a consensus on the multidisciplinary management of metastastic CRC, considering both special characteristics of our Healthcare System and international guidelines. Following discussion and online communication among the members of an executive team chosen by the Hellenic Society of Medical Oncology (HeSMO), a consensus for metastastic CRC disease was developed. Statements were subjected to the Delphi methodology on two voting rounds by invited multidisciplinary international experts on CRC. Statements reaching level of agreement by ≥80% were considered as having achieved large consensus, whereas statements reaching 60-80% moderate consensus. One hundred and nine statements were developed. Ninety experts voted for those statements. The median rate of abstain per statement was 18.5% (range: 0-54%). In the end of the process, all statements achieved a large consensus. The importance of centralization, care by a multidisciplinary team, adherence to guidelines, and personalization is emphasized. R0 resection is the only intervention that may offer substantial improvement in the oncological outcomes.

Minimally Invasive Liver Surgery for Hepatic Colorectal Metastases

Minimally invasive surgery has been cautiously introduced in surgical oncology over the last two decades due to a concern of compromised oncological outcomes. Recently, it has been adopted in liver surgery for colorectal metastases. Colorectal cancer is a major cause of cancer-related death in the USA. In addition, liver metastasis is the most common site of distant disease and its resection improves survival. While open resection was the standard of care, laparoscopic liver surgery has become the standard of care for minor liver resections. Laparoscopic liver surgery provides equivalent oncological outcomes with better perioperative results compared to open liver surgery. Robotic liver surgery has been introduced as it is believed to overcome some of the limitations of laparoscopy. Finally, laparoscopic radio-frequency ablation and microwave coagulation can be used as adjuncts in minimally invasive surgery to complement or replace surgical resection when not possible.

Advances in understanding of colorectal liver metastasis and implications for the clinic

Colorectal cancer is one of the most common cancers in both the USA and Europe. Over the course of diagnosis, treatment and surveillance, up to 50% of these patients will develop metastases to their liver. In the past 20 years alone, there have been multiple advances in the management of these colorectal metastases to the liver. These advances have been made in characterization of these tumors, diagnosis and in treatment, both locally and systemically. Because of this progress, there are subsets of patients with this stage IV disease who are cured of their disease. While significant progress has been made, there still exist limitations in the management of metastatic colorectal cancer to the liver. This review outlines current strategies and highlights recent advances in the management of colorectal liver metastases.

Colorectal hepatic metastasis: Evolving therapies

The approach for colorectal hepatic metastasis has advanced tremendously over the past decade. Multidrug chemotherapy regimens have been successfully introduced with improved outcomes. Concurrently, adjunct multimodal therapies have improved survival rates, and increased the number of patients eligible for curative liver resection. Herein, we described major advancements of surgical and oncologic management of such lesions, thereby discussing modern chemotherapeutic regimens, adjunct therapies and surgical aspects of liver resection.

Patterns of recurrence following selective intraoperative radiofrequency ablation as an adjunct to hepatic resection for colorectal liver metastases

BACKGROUND AND OBJECTIVES

The purpose of this study was to analyze the patterns of recurrence following intraoperative radiofrequency ablation (RFA) combined with hepatic resection for patients with colorectal liver metastases (CLM).

METHODS

Patients undergoing liver resection (with or without RFA) for CLM were examined. Rates and patterns of disease recurrence, as well as overall survival were assessed using Kaplan-Meier and Cox analyses.

RESULTS

A total of 174 patients underwent liver resection for CLM (150 without and 24 with intraoperative RFA). RFA was used to treat 41 tumors (median 1.6 cm). The 3-year overall survival was 65.5% and 61.4% (adjusted HR 1.02, 95% CI 0.55-1.88). Median recurrence-free survival was 7.4 versus 12.7 months with RFA versus non-RFA, respectively (adjusted HR 1.51, 95% CI 0.94-4.42). On multivariate analysis, neither survival nor recurrence-free survival was significantly associated with RFA. In total, there were two RFA ablation zone local failures. An ablation site recurrence was the sole site in one patient (4.2%).

CONCLUSION

RFA was used as an adjunct to resection in patients with greater disease burden. Despite this, RFA was not significantly associated with a higher risk of local failure and was not associated with worse survival, when compared with liver resection alone.

A retrospective comparison of microwave ablation vs. radiofrequency ablation for colorectal cancer hepatic metastases

BACKGROUND

Microwave (MWA) and radiofrequency ablation (RFA) are the most commonly used techniques for ablating colorectal-liver metastases (CRLM). The technical and oncologic differences between these modalities are unclear.

METHODS

We conducted a matched-cohort analysis of patients undergoing open MWA or RFA for CRLM at a tertiary-care center between 2008 and 2011; the primary endpoint was ablation-site recurrence. Tumors were matched by size, clinical-risk score, and arterial-intrahepatic or systemic chemotherapy use. Outcomes were compared using conditional logistic regression and stratified log-rank test.

RESULTS

We matched 254 tumors (127 per group) from 134 patients. MWA and RFA groups were comparable by age, gender, median number of tumors treated, proximity to major vessels, and postoperative complication rates. Patients in the MWA group had lower ablation-site recurrence rates (6% vs. 20%; P < 0.01). Median follow-up, however, was significantly shorter in the MWA group (18 months [95% confidence interval 17-20] vs. 31 months [95% confidence interval 28-35]; P < 0.001). Kaplan-Meier estimates of ablation-site recurrence at 2 years were significantly lower for the lesions treated with MWA (7% vs. 18%, P: 0.01).

CONCLUSIONS

Ablation-site recurrences of CRLM were lower with MWA compared with RFA in this matched cohort analysis. Longer follow-up time in the MWA may increase the recurrence rate; however, actuarial local failure estimations demonstrated better local control with MWA.

Laparoscopic-assisted ablation of hepatic tumors: a review

Thermal ablation of hepatic tumors has been an evolving field over the last two decades. It is used in the treatment of both primary and metastatic neoplasms, and with evolutions in the technology, there has been an increasing interest in treating lesions where hepatic resection is not an option. Laparoscopic or minimally invasive surgical procedures have also advanced during this same time period, and the interface of these tools has been associated with the genesis of a new approach for treating hepatic lesions which are located in difficult to reach locations or found immediately adjacent to other intra-abdominal organs. This review summarizes the published literature focusing on the treatment of primary and metastatic neoplasms located in the liver, including a review of outcomes.

Intraoperative ultrasound and tissue elastography measurements do not predict the size of hepatic microwave ablations

RATIONALE AND OBJECTIVES

Image-guided thermal ablation is used to treat primary and secondary liver cancers. Evaluating completeness of ablation is difficult with standard intraoperative B-mode ultrasound. This study evaluates the ability of B-mode ultrasound (US) and tissue elastography to adequately measure the extent of ablation compared to pathologic assessment.

MATERIALS AND METHODS

An in vivo porcine model was used to compare B-mode ultrasonography and elastography to pathologic assessment of the microwave ablation zone area. In parallel, intraoperative ablations in patients were used to assess the ability of B-mode US and elastographic measures of tissue strain immediately after ablation to predict ablation size, compared to postprocedural computed tomography (CT).

RESULTS

In the animal model, ablation zones appeared to decrease in size when monitored with ultrasound over a 10-minute span with both B-mode US and elastography. Both techniques estimated smaller zones than gross pathology, however, the differences did not reach statistical significance. Biopsies from the edges of the ablation zone, as assessed by US, contained viable tissue in 75% of the cases. In the human model, B-mode US and elastography estimated similar ablation sizes; however, they underestimate the final size of the ablation defect as measured on postprocedure CT scan (median area [interquartile range]: CT, 7.3 cm(2) [5.2-9.5] vs. US 3.6 cm(2) [1.7-6.3] and elastography 4.1 cm(2) [1.4-5.1]; P = .005).

CONCLUSIONS

Ultrasound and elastography provide an accurate gross estimation of ablation zone size but are unable to predict the degree of cellular injury and significantly underestimate the ultimate size of the ablation.

CT-guided percutaneous microwave ablation of liver metastases from nasopharyngeal carcinoma

PURPOSE

To access efficacy of percutaneous microwave ablation (MWA) of liver metastases from nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

From March 2007 to June 2012, 18 consecutive patients with NPC and liver metastases (15 men and three women; average age, 45.7 y; age range, 31-61 y) received computed tomography (CT)-guided percutaneous MWA treatment. A total of 27 ablations were performed involving 24 liver metastatic lesions in 18 patients with NPC. Average patient follow-up after ablation was 22.4 months (range, 2-52 mo). The average number of liver metastases per patient was 1.3 (range, 1-4 lesions), with lesion diameters ranging from 1.9 cm to 4.2 cm. Evaluation was then performed to assess percentage of complete necrosis, local tumor progression, and safety.

RESULTS

Technical success was achieved in all 27 MWA procedures performed. During follow-up, new metastatic lesions developed in four of 18 patients. Of these, two were liver metastases, and were successfully treated with repeat WMA. Only two major complications were observed: pneumothorax in a patient with an ablation pathway involving the thorax and postprocedural pain in two other patients. A median overall survival time of 41.4 months was observed (range, 2-50 mo); three of 18 patients died during follow-up.

CONCLUSIONS

CT-guided MWA is safe and offers an effective treatment alternative for local tumor control in selected patients with liver metastases from NPC.

Locoregional surgical and interventional therapies for advanced colorectal cancer liver metastases: expert consensus statements

Selection of the optimal surgical and interventional therapies for advanced colorectal cancer liver metastases (CRLM) requires multidisciplinary discussion of treatment strategies early in the trajectory of the individual patient's care. This paper reports on expert consensus on locoregional and interventional therapies for the treatment of advanced CRLM. Resection remains the reference treatment for patients with bilateral CRLM and synchronous presentation of primary and metastatic cancer. Patients with oligonodular bilateral CRLM may be candidates for one-stage multiple segmentectomies; two-stage resection with or without portal vein embolization may allow complete resection in patients with more advanced disease. After downsizing with preoperative systemic and/or regional therapy, curative-intent hepatectomy requires resection of all initial and currently known sites of disease; debulking procedures are not recommended. Many patients with synchronous primary disease and CRLM can safely undergo simultaneous resection of all disease. Staged resections should be considered for patients in whom the volume of the future liver remnant is anticipated to be marginal or inadequate, who have significant medical comorbid condition(s), or in whom extensive resections are required for the primary cancer and/or CRLM. Priority for liver-first or primary-first resection should depend on primary tumour-related symptoms or concern for the progression of marginally resectable CRLM during treatment of the primary disease. Chemotherapy delivered by hepatic arterial infusion represents a valid option in patients with liver-only disease, although it is best delivered in experienced centres. Ablation strategies are not recommended as first-line treatments for resectable CRLM alone or in combination with resection because of high local failure rates and limitations related to tumour size, multiplicity and intrahepatic location.

Patterns of recurrence after ablation of colorectal cancer liver metastases

PURPOSE

To determine the local recurrence rate and factors associated with recurrence after intraoperative ablation of colorectal cancer liver metastases.

METHODS

A retrospective analysis of a prospectively maintained database was performed for patients who underwent ablation of a hepatic colorectal cancer metastasis in the operating room from April 1996 to March 2010. Kaplan-Meier survival curves and Cox models were used to determine recurrence rates and assess significance.

RESULTS

Ablation was performed in 10% (n = 158 patients) of all cases during the study period. Seventy-eight percent were performed in conjunction with a liver resection. Of the 315 tumors ablated, most tumors were ≤ 1 cm in maximum diameter (53%). Radiofrequency ablation was used to treat most of the tumors (70%). Thirty-six tumors (11%) had local recurrence as part of their recurrence pattern. Disease recurred in the liver or systemically after 212 tumors (67%) were ablated. On univariate analysis, tumor size greater than 1 cm was associated with a significantly increased risk of local recurrence (hazard ratio 2.3, 95% confidence interval 1.2-4.5, P = 0.013). The 2 year ablation zone recurrence-free survival was 92% for tumors ≤ 1 cm compared to 81% for tumors >1 cm. On multivariate analysis, tumor size of >1 cm, lack of postoperative chemotherapy, and use of cryotherapy were significantly associated with a higher local recurrence rate.

CONCLUSIONS

Intraoperative ablation appears to be highly effective treatment for hepatic colorectal tumors ≤ 1 cm.

Outcome of laparoscopic major liver resection for colorectal metastases

BACKGROUND

Minimally invasive liver resection (MILR) for colorectal liver metastases (CRLM) is gaining widespread acceptance. However, data are still lacking on the feasibility, long- and short-term outcomes of laparoscopic major hepatectomy (i.e., three or more liver segments).

METHODS

Between October 2002 and December 2008, prospectively collected data of 117 patients who underwent major liver resection [97 open (OMLR) and 20 laparoscopic (LMLR) procedures] for CRLM were analyzed. Twenty patients in the LMLR group were matched with 20 patients of the OMLR based on 13 parameters. We compared the long- and short-term outcomes between these two groups.

RESULTS

Median duration of surgery was 257.5 (range 75-360) min in LMLR versus 232.5 (range 120-400) min in OMLR (P = 0.228). Median blood loss during surgery was 550 ml in each group (range 100-4,000 vs. 100-2,500 ml, P = 0.884). There was no statistically significant difference in the rate of postoperative complications (both severity and location). Median magnitude of tumor-free resection margin was 7.5 versus 5.5 mm in the laparoscopy versus open group, respectively (P = 0.651). Median disease-free survival (DFS) of the entire study population was 18.4 months [95% confidence interval (CI) 11.9-50.0 months]. Median overall survival (OS) was 50.7 months (95% CI 36.2 months to undetermined). The estimated DFS and OS rates at 1, 2, and 5 years were comparable in the two groups (P = 0.637 and 0.872, respectively).

CONCLUSION

Laparoscopic MLR for selected CRLM is feasible and might result in comparable oncologic outcomes as in open liver resection.

Minimally invasive liver surgery for metastases from colorectal cancer: oncologic outcome and prognostic factors

BACKGROUND

Few reports exist on long-term survival after minimally invasive liver surgery (MILS) for colorectal liver metastases (CRLM). No data are available assessing prognostic factors in the era of current modern treatment strategies.

METHODS

Between October 2002 and December 2008, 274 consecutive patients were analyzed on an intention-to-treat basis. Open liver surgery (OLS) was performed in 193 patients for a total of 437 metastases, and MILS was performed in 81 patients for 176 metastases. Systemic chemotherapy was administered preoperatively in 173 and postoperatively in 174 patients. The impact of 23 potential prognostic factors on disease-free (DFS) and overall survival (OS) was evaluated using univariable and multivariable Cox regression models.

RESULTS

Postoperative complications were observed in 54 patients after OLS and in 11 after MILS (p = 0.016). The median postoperative length of hospital stay was 9 days after OLS and 5 days after MILS (p < 0.0001). For the entire patient population, the 5 year DFS and OS rates were 29.9 and 59.5%, respectively. No differences in survival between patients treated with MILS and OLS were observed (p = 0.63). In univariable analyses, the number of liver metastases and the overall Fong's clinical risk score (CRS) were the only two variables that predicted DFS (p ≤ 0.0035) and OS (p ≤ 0.0005). In multivariable analyses, the total CRS was the only independent predictor of both DFS (p = 0.0002) and OS (p = 0.002).

CONCLUSION

The long-term oncologic outcome of surgically treated patients with CRLM is determined by the Fong's CRS. Although MILS does not influence long-term survival, it has a beneficial impact on the immediate postoperative clinical outcome.

Laparoscopic thermoablation of colorectal cancer metastases to the liver - new experience of the centre

Aim of the study

Thermoablation of metastatic lesions in the liver is very commonplace. At present there are 3 essential techniques of access to carry out the procedure: open surgery, percutaneous technique and laparoscopic method. Percutaneous thermoablation is criticised due to the possible lack of radicalism. On the other hand, thermoablation during open surgery is a big perioperative trauma for the patient. The laparoscopic technique seems to be a compromise between the aforementioned techniques. The aim of this study was to present the technique and preliminary results of thermoablation of the liver carried out by means of the laparoscopic technique.

Material and methods

Laparoscopic thermoablation was carried out in 4 patients with colorectal cancer metastases to the liver. In order to precisely locate the tumour and guarantee radicalism of the surgery, laparoscopic probe ultrasonography was carried out during the procedure.

Results

All the patients underwent the procedure without any difficulties. All the patients left the hospital department as soon as 3 or 4 days after the surgery. This was about 7 days earlier in comparison with the open surgery procedure, which had been carried out before. The patients required a supply of analgesics only during the first 48 hours – non-steroid anti-inflammatory drugs, which made a substantial difference between them and the patients treated with the open surgical technique. Thanks to the laparoscopic ultrasound technique one patient had an additional lesion located, which had not been described in preoperative examinations.

Conclusions

In combination with ultrasonography, laparoscopic access, which does not have a very invasive character, seems to be relatively simple and effective to carry out the procedure of thermoablation.