Meta-analysis of clinical outcome after first and second liver resection for colorectal metastases

Laparoscopic liver surgery: new frontiers

Laparoscopic liver resection (LHR) has shown classical advantages of minimally invasive surgery over open counterpart. In spite of introduction in early 1990's only few centres worldwide adapted LHR to routine practice. It was due to considerable technical challenges and uncertainty about oncologic outcomes. Surgical instrumentation and accumulation of surgical experience has largely enabled to solve many technical considerations. Intraoperative navigation options have also been improved. Consequently indications have been drastically expanded nearly reaching criteria equal to open liver resection in expert centres. Recent studies have verified oncologic integrity of LHR. However, mastering of LHR is still a quite demanding task limiting expansion of this patient friendly technique. This emphasizes the necessity of systematic training for laparoscopic liver surgery. This article reviews the state of the art of laparoscopic liver surgery lightening burning issues of research and clinical practice.

Colorectal liver metastases; the current scenario

Colorectal cancer is the most common gastrointestinal malignancy. When metastases occurs, it most frequently occurs in the liver. Median survival without any treatment is poor, and until recently only a subset of patients were amenable to any form of surgical therapy. The following article aims to examine recent strategies used to increase the cohort of patients coming to curative oncological surgery.

Laparoscopic resection of colorectal liver metastases: surgical and long-term oncologic outcome

OBJECTIVE

To analyze the immediate and long-term outcome after laparoscopic resection of colorectal liver metastases and difference between observed and predicted [Fong's and Basingstoke Predictive Index (BPI) scores] survivals.

BACKGROUND

: Laparoscopic liver resection has been reported safe and feasible and improves postoperative course. The oncologic outcomes after resection of colorectal metastases are poorly reported.

METHODS

Between August 1998 and January 2010, 122 patients underwent laparoscopic resection for colorectal liver metastases during 135 procedures at Rikshospitalet. Patients undergoing surgery between August 1998 and June 2009 were included in research analysis. The patients had median Fong's and BPI's scores of 2 (0-5) and 7 (0-23), respectively. Mainstream analysis of hospital data was done on intent-to-treat basis. Intraoperative incidents and postoperative complications were analyzed according to the Satava and Clavien-Dindo classifications. Median follow-up was 24 (0-100) months.

RESULTS

One hundred fifty-one liver resections were performed in 107 patients during 118 procedures: 117 nonanatomic and 34 anatomic liver resections. There were 5 conversions to laparotomy (4.2%). The resection margin was free of tumor tissue in 141 (93.4%) of 151 specimens, and the distance between the resection margin and tumor tissue was median 6 (0-40) mm. Intraoperative incidents occurred in 14 cases (11.9%), including 5 (4.2%), 8 (6.8%), and 1 (0.8%) cases of grades I, II, and III, respectively. Postoperative complications were observed in 16 cases (14.3%), including 2, 3, 7, 3, 0, and 1 cases of grades I, II, IIIa, IIIb, IV, and V, respectively. During follow-up, 21 patients received repeat liver resection of recurrences (11 by laparoscopy and 10 by laparotomy). The 5-year overall survival rates were 51% as laparoscopically completed cases and 47% as intent-to-treat. The observed actuarial survival values exceeded the values expected by Fong's and BPI's score, with 10.2% and 6.7% as laparoscopically completed cases and with 3.8% and 2.4% as intent-to-treat, respectively.

CONCLUSIONS

Laparoscopic resection is a favorable alternative to open liver resection for patients with colorectal liver metastases. The observed actuarial survival values after laparoscopic resection surpass the values expected by major scoring systems.

Intra-operative ultrasound hand-held strain imaging for the visualization of ablations produced in the liver with a toroidal HIFU transducer: first in vivo results

The use of hand-held ultrasound strain imaging for the intra-operative real-time visualization of HIFU (high-intensity focused ultrasound) ablations produced in the liver by a toroidal transducer was investigated. A linear 12 MHz ultrasound imaging probe was used to obtain radiofrequency signals. Using a fast cross-correlation algorithm, strain images were calculated and displayed at 60 frames s(-1), allowing the use of hand-held strain imaging intra-operatively. Fourteen HIFU lesions were produced in four pigs. Intra-operative strain imaging of HIFU ablations in the liver was feasible owing to the high frame rate. The correlation between dimensions measured on gross pathology and dimensions measured on B-mode images and on strain images were R = 0.72 and R = 0.94 respectively. The contrast between ablated and non-ablated tissue was significantly higher (p < 0.05) in the strain images (22 dB) than in the B-mode images (9 dB). Strain images allowed equivalent or improved definition of ablated regions when compared with B-mode images. Real-time intra-operative hand-held strain imaging seems to be a promising complement to conventional B-mode imaging for the guidance of HIFU ablations produced in the liver during an open procedure. These results support that hand-held strain imaging outperforms conventional B-mode ultrasound and could potentially be used for the assessment of thermal therapies.

Clinical impact of different detection methods for disseminated tumor cells in bone marrow of patients undergoing surgical resection of colorectal liver metastases: a prospective follow-up study

Background

Large number of patients with colorectal liver metastasis show recurrent disease after curative surgical resection. Identification of these high-risk patients may guide therapeutic strategies. The aim of this study was to evaluate whether the presence of disseminated tumor cells in bone marrow from patients undergoing surgical resection of colorectal liver metastases can predict clinical outcome.

Methods

Sixty patients with colorectal liver metastases were planned for a curative resection between 2001 and 2007. All patients underwent bone marrow aspiration before surgery. Detection of tumor cells was performed using immunocytochemical staining for cytokeratin (CK-ICC) combined with automated microscopy or indirectly using reverse transcription-polymerase chain reaction (RT-PCR).

Results

Disseminated tumor cells were found in 15 of the 46 patients (33%) using CK-ICC and in 9 of 44 of the patients (20%) using RT-PCR. Patients with negative results for RT-PCR had a significant better disease-free survival after resection of their liver metastases (p = 0.02). This group also showed significant better overall survival (p = 0.002). CK-ICC did not predict a worse clinical outcome.

Conclusions

The presence of disseminated tumor cells in bone marrow detected using RT-PCR did predict a worse clinical outcome. The presence of cells detected with CK-ICC did not correlate with poor prognosis.

Comparison of clinical risk scores predicting prognosis after resection of colorectal liver metastases

BACKGROUND

The aim of this study was to compare the risk scores of Fong et al., Nordlinger et al., and the TNM classification of colorectal liver metastases proposed by the UICC.

METHODS

Data from 282 consecutive patients undergoing 303 liver resections for metastatic colorectal cancer between 1995 and 2006 at the Department of Surgery, University of Erlangen were analyzed. The median follow-up time was 34 months. A curative (R0) resection was performed in 92% of the patients.

RESULTS

Applying the clinical risk score of Fong with preoperative data identified three risk groups. The survival rates between "low risk" (n = 22) and "intermediate risk" (n = 222) diverged (P = 0.073). The survival rates between "intermediate risk" and "high risk" (n = 59) differed significantly (P = 0.030). Using the risk scoring system of Nordlinger, patients were divided into two risk groups (i.e., "low risk" (n = 218) and "intermediate risk" (n = 68)). Significant differences in survival between the groups were noted (P = 0.012). Applying the clinical TNM classification of colorectal liver metastases revealed no significant differences in survival between the risk groups.

CONCLUSIONS

Our study found the clinical risk score developed by Fong et al. to be a reliable preoperative prognostic tool for selecting patients for surgical resection of colorectal liver metastases.

Treatment for colorectal liver metastases: a review

INTRODUCTION

Over the past decade, the emergence of surgical adjuncts such as portal vein embolization, two-stage hepatectomy, and ablative therapies not only decreases mortality and morbidity after an extended hepatectomy but also broadens the indication for surgical treatment of liver metastasis from colorectal cancer. Combination chemotherapeutic regimens, namely 5-fluorouracil/folinic acid with irinotecan or oxaliplatin, and targeted monochromal antibodies can downsize the tumor burden to the extent that formerly unresectable metastases can sometimes be excised.

DISCUSSION

The 5-year survival rate following liver resection ranges between 25% and 58%. During the 5-fluorouracil/folinic acid with oxaliplatin and 5-fluorouracil/folinic acid with irinotecan treatment period, the patients who were deemed to be resectable should be considered as surgical candidates regardless of the associated adverse predictive factors. The emergence of epidermal growth factor receptor antibody agents, which act effectively in patients with Kras wild-type tumor, fosters treatment individualization.

CONCLUSION

The efficacy of the perioperative chemotherapy on survival benefit for resectable liver metastases has not been justified. However, the timing and indication of surgical treatment paradigm in colorectal liver metastasis, including for synchronous disease and extrahepatic disease, are dramatically changing with the development of chemotherapeutic agents.

Hepatic metastasectomy for testicular germ cell tumors: is it worth it?

BACKGROUND

Chemotherapy is highly effective for metastatic germ cell tumor (GCT), but experience with resection of hepatic metastases from GCT is limited.

METHODS

Fifteen patients with GCT metastatic to the liver underwent 16 hepatic operations (1975-2002). Pre-resection therapy, surgical pathology, and operative outcomes were reviewed. All patients were followed to death or last contact for survival and disease status.

RESULTS

Patients underwent biopsy (three), wedge resection (nine), bisegmentectomy (two), and major lobectomy (two). Hepatic histology included: necrosis (33%), viable tumor (27%), mature teratoma (13%), and benign histology (27%). Concomitant resection of extrahepatic disease (14 patients, 93%) found necrosis (53%), mature teratoma (27%), and viable tumor (13%). Operative mortality was 0% and morbidity was 40%. At 8.2 years (mean) from resection, 11 patients (73%) were alive: five with no evidence of disease, two with elevated tumor marker only, and four with gross disease. Four patients (27%) died. The 10-year overall survival was 62% from diagnosis.

CONCLUSION

Resection of post-chemotherapy hepatic disease is safe, even when combined with resection of extrahepatic residual disease. The varied histologic findings, lack of reliable predictors, and prolonged survival achieved support a multidisciplinary approach which includes surgical resection of hepatic metastases.

Thermal ablation by high-intensity-focused ultrasound using a toroid transducer increases the coagulated volume. Results of animal experiments

Surgical resection is the only treatment of colorectal liver metastases that can ensure long-term survival and cure in some patients. However, only 20% of patients are suitable for surgery. As a result, many nonresectional modalities of treatment have been assessed to provide an alternative to liver resection. Several limitations have been observed when using these techniques and available evidence is limited. Here, we report that a new design of high intensity focused ultrasound transducer can significantly enlarge the coagulated volume over short periods of time and that treatment in the liver can be guided in real-time using an integrated ultrasound imaging probe. Our long-term objective is to develop a device that can be used during surgery for eventual clinical use in conjunction with resection. Eight ultrasound emitters, divided into 256 elements, were created by sectioning a single toroid piezocomposite transducer. The focal zone was conical in shape and located 70 mm from the transducer; enabling the treatment of deep-seated tumors. A single thermal lesion was created when the eight emitters performed alternative and consecutive 5-s ultrasound exposures. This article presents in vivo evidence that the coagulated volume obtained from a 40 s total exposure in the liver was 7.0 +/- 2.5 cm(3) (minimum 1.5 - maximum 20.0 cm(3)) with an average diameter of 17.5 +/- 3.8 mm (minimum 10.0 - maximum 29.0 mm). All lesions were visible with high contrast on sonograms. The correlation between the diameter of lesions observed on sonograms and during gross examination was 92%. This method also allowed the user to easily enlarge the coagulated volume by juxtaposing single lesions. This approach may have a role in treating unresectable colorectal liver metastases and may also be used in conjunction with resection to extend its limits.

Impact of type of liver resection on the outcome of colorectal liver metastases: a case-matched analysis

BACKGROUND

Wedge resection (WR) for colorectal liver metastases (CLM) has become more common in an attempt to preserve liver parenchyma. However, some investigator have reported that WR is associated with a higher incidence of positive margin and an inferior survival compared with anatomic resection (AR) 1.

OBJECTIVES

This study evaluated survival, margin status, and pattern of recurrence of patients with CLM treated with WR or AR.

METHODS

We identified 208 consecutive patients, in a single institutional database from 1995 to 2004, who underwent either WR or AR. WR was defined as a nonanatomic resection and AR was defined as single resection of one or two liver segments. Patients with combined WR-AR and patients requiring resection of more than two segments or radiofrequency ablation were excluded from the analysis.

RESULTS

One hundred six patients underwent WR and 102 patients had AR. There were no differences in the rate of positive surgical margin (P = 0.146), overall recurrence rates (P = 0.211), and patterns of recurrence between the two groups (P = 0.468). The median survival was 32 months for WR and 42 for AR, with 5-year survival rates of 29% and 27% respectively, with no significant difference (P = 0.308). Morbidity was similar between the two groups.

CONCLUSIONS

WR is a safe procedure and does not disadvantage the patients in terms of tumor recurrence and overall survival.

Quantification of risk of a positive (R1) resection margin following hepatic resection for metastatic colorectal cancer: an aid to clinical decision-making

BACKGROUND AND AIMS

Margin involvement following liver resection for colorectal cancer is associated with early disease recurrence and shorter long-term survival. This study aimed to develop a predictive index for quantifying the likelihood of a positive resection margin (R1) for patients undergoing hepatic resection for metastatic colorectal cancer.

METHODS

Clinical, pathological and complete follow-up data were prospectively collected from 1005 consecutive liver resections performed in 929 patients for colorectal liver metastases with curative intent at a single centre between 1987 and 2005. Ninety-four resections in 81 patients with extra-hepatic disease were excluded, leaving 911 resections (844 primary and 67 repeat) in 848 patients for analysis. Multivariate logistic regression was used to identify independent predictors of margin involvement and from the beta-coefficients generated, develop a predictive model that was validated using measures of discrimination and calibration.

RESULTS

There were 80 (8.8%) R1 resections, with a 5-year cancer-specific survival for R0 and R1 hepatic resections of 39.7% and 17.8%, respectively; p<0.001. On multivariate analysis, five risk factors were found to be independent predictors of an R1 resection: non-anatomical resection vs. anatomical resection (odds ratio (OR)=4.3, p=0.001), >3 hepatic metastases involving >50% of the liver vs. <3 metastases (OR=4.0, p<0.001); bilobar vs. unilobar disease (OR=2.9, p<0.001); repeat vs. primary hepatic resection (OR=3.1, p=0.006); abnormal vs. normal pre-operative liver function tests (OR=1.6, p=0.044). These five factors were used to develop a predictive model, which when tested, fitted the data well, with an area under the receiver operating characteristic curve of 78.1% (S.E.=2.7%).

CONCLUSIONS

This study describes an accurate model for quantifying the risk of a positive margin following hepatic resection for liver metastases. It may be used pre-operatively by multi-disciplinary teams to identify patients who may benefit from neoadjuvant therapy prior to liver surgery, thus minimizing the risk of a positive resection margin.

Systematic reviews and meta-analyses in coloproctology: interpretation and potential pitfalls

A systematic review (SR) is the unbiased appraisal of systematically identified relevant studies. Implicit in its definition is a robust and scientifically valid process, and when performed as such, SR is an important clinical research tool and influence in health policy decision-making. This educational paper outlines that, from the original prototype based on randomized trials, there are now many other types of SRs including those based on: nonrandomized comparative studies, observational studies, prognostic studies, and studies of diagnostic and screening tools. While each of these has a similar 'anatomy' or format, at an individual class level, there are principles specific to each SR type. Several examples from the coloproctology literature are used as case-studies to illustrate potential pitfalls, and upon re-analysis, often reverse or attenuate the conclusions stated in the original publication. These examples serve to emphasize the need for health professionals to understand the process of SR and meta-analysis so that we all arrive at appropriate interpretations to the benefit of our patients.

Positron emission tomography/computer tomography: Challenge to conventional imaging modalities in evaluating primary and metastatic liver malignancies

Computer tomography (CT) and magnetic resonance imaging (MRI), as conventional imaging modalities, are the preferred methodology for tumor, nodal and systemic metastasis (TNM) staging. However, all the noninvasive techniques in current use are not sufficiently able to identify primary tumors and even unable to define the extent of metastatic spread. In addition, relying exclusively on macromorphological characteristics to make a conclusion runs the risk of misdiagnosis due mainly to the intrinsic limitations of the imaging modalities themselves. Solely based on the macromorphological characteristics of cancer, one cannot give an appropriate assessment of the biological characteristics of tumors. Currently, positron emission tomography/computer tomography (PET/CT) are more and more widely available and their application with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) in oncology has become one of the standard imaging modalities in diagnosing and staging of tumors, and monitoring the therapeutic efficacy in hepatic malignancies. Recently, investigators have measured glucose utilization in liver tumors using ¹⁸F-FDG, PET and PET/CT in order to establish diagnosis of tumors, assess their biologic characteristics and predict therapeutic effects on hepatic malignancies. PET/CT with ¹⁸F-FDG as a radiotracer may further enhance the hepatic malignancy diagnostic algorithm by accurate diagnosis, staging, restaging and evaluating its biological characteristics, which can benefit the patients suffering from hepatic metastases, hepatocellular carcinoma and cholangiocarcinoma.