Colorectal carcinoma metastases to the liver. Does primary tumor location affect its lobar distribution?

Anatomical resection improves relapse-free survival in colorectal liver metastases in patients with KRAS/NRAS/BRAF mutations or right-sided colon cancer: a retrospective cohort study

BACKGROUND

The type of liver resection (anatomical resection, AR or non-anatomical resection, NAR) for colorectal liver metastases (CRLM) is subject to debate. The debate may persist because some prognostic factors, associated with aggressive tumor biological behavior, have been overlooked.

OBJECTIVE

Our study aimed to investigate the characteristics of patients who would benefit more from anatomical resection for CRLM.

METHODS

Seven hundred twenty-nine patients who underwent hepatic resection of CRLM were retrospectively collected from June 2012 to May 2019. Treatment effects between AR and NAR were compared in full subgroup analyses. Tumor relapse-free survival (RFS) was evaluated by a stratified log-rank test and summarized with the use of Kaplan-Meier and Cox proportional hazards methods.

RESULTS

Among 729 patients, 235 (32.2%) underwent AR and 494 (67.8%) underwent NAR. We showed favorable trends in RFS for AR compared with NAR in the patients with KRAS/NRAS/BRAF mutation (interaction P <0.001) or right-sidedness (interaction P <0.05). Patients who underwent AR had a markedly improved RFS compared with NAR in the cohorts of RAS/NRAS/BRAF mutation (median RFS 23.2 vs. 11.1 months, P <0.001) or right-sidedness (median RFS 31.6 vs. 11.5 months, P <0.001); upon the multivariable analyses, AR [gene mutation: hazard ratio (HR)=0.506, 95% CI=0.371-0.690, P <0.001; right-sidedness: HR=0.426, 95% CI=0.261-0.695, P =0.001) remained prognostic independently. In contrast, patients who underwent AR had a similar RFS compared with those who underwent NAR, in the cohorts of patients with gene wild-type tumors (median RFS 20.5 vs. 21.6 months, P =0.333). or left-sidedness (median RFS 15.8 vs. 19.5 months, P =0.294).

CONCLUSIONS

CRLM patients with gene mutation or right-sidedness can benefit more from AR rather than from NAR.

Impact of anatomical liver resection on patient survival in KRAS-wild-type colorectal liver metastasis: A multicenter retrospective study

BACKGROUND

Liver resection is a standard therapy for colorectal liver metastasis. However, the impact of anatomical resection and nonanatomical resection on the survival in patients with Kirsten rat sarcoma-wild-type and Kirsten rat sarcoma-mutated colorectal liver metastasis remain unclear. We investigated whether anatomical resection versus nonanatomical resection improves survival in colorectal liver metastasis stratified by Kirsten rat sarcoma mutational status.

METHODS

Among 639 consecutive patients with colorectal liver metastasis who underwent primary liver resection between January 2008 and December 2017, 349 patients were excluded due to their unknown Kirsten rat sarcoma mutational status, or due to receiving anatomical resection with concomitant non-anatomical resection, radiofrequency, or R2 resection. Accordingly, 290 patients with colorectal liver metastasis were retrospectively assessed. The relationships between resection types and survival were investigated in Kirsten rat sarcoma-wild-type and -mutated groups.

RESULTS

Anatomical resection was performed in 77/186 (41%) and 44/104 (42%) patients with Kirsten rat sarcoma-wild-type and Kirsten rat sarcoma-mutated genetic statuses, respectively. For both, the clinical-pathologic factors were comparable, except a larger maximum tumor size and surgical margin were observed in anatomical resection cases. Anatomical resection patients had significantly longer recurrence-free survival and overall survival than nonanatomical resection cases in the Kirsten rat sarcoma-wild-type group (recurrence-free survival, P < .001; overall survival, P = .005). No significant recurrence-free survival or overall survival differences were observed between Kirsten rat sarcoma-mutated anatomical resection and non-anatomical resection (recurrence-free survival, P = .132; overall survival, P = .563). Although, intrahepatic recurrence in Kirsten rat sarcoma-wild-type and -mutated colorectal liver metastasis was comparable (P = .973), extrahepatic recurrence was increased in Kirsten rat sarcoma-mutated versus -wild-type colorectal liver metastasis (P < .001).

CONCLUSION

In contrast to Kirsten rat sarcoma-mutated colorectal liver metastasis with higher extrahepatic recurrence after liver resection, local liver control via anatomical resection improved the postoperative survival in patients with Kirsten rat sarcoma-wild-type colorectal liver metastasis.

Segmental Distribution of Hepatocellular Carcinoma in Cirrhotic Livers

Background: To evaluate the segmental distribution of hepatocellular carcinoma (HCC) according to Couinaud’s anatomical division in cirrhotic patients. Methods: Between 2020 and 2021, a total of 322 HCC nodules were diagnosed in 217 cirrhotic patients who underwent computed tomography (CT) or magnetic resonance imaging (MRI) for the evaluation of suspicious nodules (>1 cm) detected during ultrasound surveillance. For each patient, the segmental position of the HCC nodule was recorded according to Couinaud’s description. The clinical data and nodule characteristics were collected. Results: A total of 234 (72.7%) HCC nodules were situated in the right lobe whereas 79 (24.5%) were detected in the left lobe (p < 0.0001) and only 9 nodules were in the caudate lobe (2.8%). HCC was most common in segment 8 (n = 88, 27.4%) and least common in segment 1 (n = 9, 2.8%). No significant differences were found in the frequencies of segmental or lobar involvement considering patient demographic and clinical characteristics, nodule dimension, or disease appearance. Conclusions: The intrahepatic distribution of HCC differs among Couinaud’s segments, with segment 8 being the most common location and segment 1 being the least common. The segmental distribution of tumour location was similar to the normal liver volume distribution, supporting a possible correlation between HCC location and the volume of hepatic segments and/or the volumetric distribution of the portal blood flow.

Parenchymal Sparing Anatomical Liver Resections With Full Laparoscopic Approach: Description of Technique and Short-term Results

OBJECTIVE

The aim of this study was to describe laparoscopic anatomical parenchymal sparing liver resections for hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM) and report the short-term outcomes.

BACKGROUND

Anatomical resections (ARs) have better oncological outcomes compared to partial resections in patients with HCC, and some suggest should be performed also for CRLM as micrometastasis occurs through the intrahepatic structures. Furthermore, remnant liver ischemia after partial resections has been associated with worse oncological outcomes. Few experiences on laparoscopic anatomical resections have been reported and no data on limited AR exist.

METHODS

We performed a retrospective analysis of 86 patients undergoing full laparoscopic anatomical parenchymal sparing resections with preoperative surgical simulation and standardized procedures.

RESULTS

A total of 55 patients had HCC, whereas 31 had CRLM with a median of 1 lesion and a size of 30 mm. During preoperative three-dimensional (3D) simulation, a median resection volume of 120 mL was planned. Sixteen anatomical subsegmentectomies, 56 segmentectomies, and 14 sectionectomies were performed. Concordance between preoperative 3D simulation and intraoperative resection was 98.7%. Two patients were converted, and 7 patients experienced complications. Subsegmentectomies had comparable blood loss (166 mL, P = 0.59), but longer operative time (426 min, P = 0.01) than segmentectomies (blood loss 222 mL; operative time 355 min) and sectionectomies (blood loss 120 mL; operative time 295 min). R0 resection and margin width remained comparable among groups.

CONCLUSIONS

A precise preoperative planning and a standardized surgical technique allow to pursue the oncological quality of AR enhancing the safety of the parenchyma sparing principle, reducing surgical stress through a laparoscopic approach.

Evaluation of accuracy of laparoscopic liver mono-segmentectomy using the Glissonian approach with indocyanine green fluorescence negative staining by comparing estimated and actual resection volumes: A single-center retrospective cohort study

BACKGROUND/PURPOSE

Laparoscopic liver mono-segmentectomy (LLMS) may improve patient outcomes, but it is difficult and its accuracy and safety are unknown. We evaluated the accuracy of LLMS using Glissonian approach with indocyanine green fluorescence (ICG) negative staining.

METHODS

Seventy-four patients eligible for LLMS except for segment 1 were enrolled. Preoperative three-dimensional CT-based surgical simulation was used to determine estimated liver resection volume (ELRV), which was compared with modified actual liver resection volume (ALRV) obtained from actual liver resection mass. The LLMS accuracy was also evaluated based on operator's experience (attending surgeon [AS] or trainee surgeon [TS]).

RESULTS

Estimated liver resection volumes significantly correlated with ALRVs (r = .82) in all cases. Moreover, TS-conducted LLMS also showed acceptable difference between ELRV and ALRV compared with AS-conducted LLMS. There were no intergroup differences in estimated blood loss, operation time, time of Pringle maneuver, postoperative complications, and length of postoperative hospitalization (P < .05). Moreover, R0 resection was comparable between the AS and TS groups.

CONCLUSIONS

Laparoscopic liver mono-segmentectomy with Glissonian approach using ICG negative imaging ensured safe and accurate procedure owing to facilitated visualization of the resection line. Our approach was effective in avoiding postoperative liver dysfunction and securing radical resection. In addition, it might be helpful in TS education of LLMS.

Anatomical Versus Nonanatomical Resection for Colorectal Liver Metastasis

BACKGROUND

Anatomical resection (AR) for colorectal liver metastasis (CLM) is disputable. We investigated the impact of AR on short-term outcomes and survival in CLM patients.

METHODS

Patients having hepatectomy with AR or nonanatomical resection (NAR) for CLM were reviewed. Comparison was made between AR and NAR groups. Group comparison was performed again after propensity score matching with ratio 1:1.

RESULTS

AR group (n = 234 vs n = 89 in NAR group) had higher carcinoembryonic antigen level (20 vs 7.8 ng/mL, p ≤ 0.001), more blood loss (0.65 vs 0.2 L, p < 0.001), more transfusions (19.2% vs 3.4%, p = 0.001), longer operation (339.5 vs 180 min, p < 0.001), longer hospital stay (9 vs 6 days, p < 0.001), more tumors (p < 0.001), larger tumors (4 vs 2 cm, p < 0.001), more bilobar involvement (20.9% vs 7.9%, p = 0.006), and comparable survival (overall, p = 0.721; disease-free, p = 0.695). After propensity score matching, each group had 70 patients, with matched tumor number, tumor size, liver function, and tumor marker. AR group had more open resections (85.7% vs 68.6%, p = 0.016), more blood loss (0.556 vs 0.3 L, p = 0.001), more transfusions (17.1% vs 4.3%, p = 0.015), longer operation (310 vs 180 min, p < 0.001), longer hospital stay (8.5 vs 6 days, p = 0.002), comparable overall survival (p = 0.819), and comparable disease-free survival (p = 0.855).

CONCLUSION

Similar disease-free survival and overall survival of CLM patients were seen with the use of AR and NAR. However, AR may entail a more eventful postoperative course. NAR with margin should be considered whenever feasible.

Is it possible to predict the side of hepatic metastases according to the primary location of colorectal cancer?

PURPOSE

The aim of this study was to investigate the impact of the primary location of colorectal adenocarcinoma on the lobar distribution of its hepatic metastases based on the streamline hypothesis.

MATERIAL AND METHODS

The hospital database was utilised to identify the colorectal cancer patients. Eighty-six patients diagnosed with colorectal adenocarcinoma, who had hepatic metastases on the initial diagnostic stage or on the follow-up investigations, were enrolled the study. Computed tomography (CT) images of the study population were reviewed for the primary location of the colorectal tumour, and the side and number of hepatic metastases.

RESULTS

A total of 481 metastases were counted on CT from 22 right-sided and 64 left-sided colon tumours. The ratio of right-to-left hemiliver involvement was 1.97 : 1 for whole study population. The right-to-left ratio was calculated as 1.55 : 1 for right colon tumours and 2.17 : 1 for left colon tumours (p = 0.106). In the subgroup analysis with unilobar metastatic patients, again there was no significant difference in terms of the colorectal tumours' primary location (p = 0.325).

CONCLUSIONS

The lobar distribution of hepatic metastases from colorectal adenocarcinoma may not be associated with the primary tumour localisation.

Liver metastasis in colorectal cancer: evaluation of segmental distribution

Introduction

It is known that the liver is the main target for metastasis in colorectal cancer. However, we do not know enough from the literature to describe the segmental distribution of liver metastatic lesions of colorectal cancers.

Aim

To investigate which liver segment is affected.

Material and methods

A total of 326 patients (female/male, n = 115/221; age: 53 ±8/51 ±7 years) were included in our study, classified according to their pathological diagnosis. After liver metastases of the patients were determined, they were divided according to Couinaud classification.

Results

While the total number of metastases detected in the right lobe was 691 (70.1%), the number of metastases detected in the left lobe was 294 (29.9%), and the difference was highly significant (p < 0.0001). Metastases in the right lobe anterior segment amounted to 279 (40.4%), and metastasis in right lobe posterior segment was 412 (59.6%), and the difference was significant. When the total number of metastatic lesions is evaluated by excluding segment I, the largest number of lesions were observed in segment VIII. The liver segments with the highest number of metastatic lesions were, respectively, VII, IV, VI, V, III, and II. In this case, the fewest metastatic lesions were observed in segment II.

Conclusions

Liver metastases of colorectal cancer are more common in the right lobe than in the left lobe. The right lobe posterior segment (segment VI) is the main target of metastases.

Liver metastasis in colorectal cancer: evaluation of segmental distribution

INTRODUCTION

It is known that the liver is the main target for metastasis in colorectal cancer. However, we do not know enough from the literature to describe the segmental distribution of liver metastatic lesions of colorectal cancers.

AIM

To investigate which liver segment is affected.

MATERIAL AND METHODS

A total of 326 patients (female/male, n = 115/221; age: 53 ±8/51 ±7 years) were included in our study, classified according to their pathological diagnosis. After liver metastases of the patients were determined, they were divided according to Couinaud classification.

RESULTS

While the total number of metastases detected in the right lobe was 691 (70.1%), the number of metastases detected in the left lobe was 294 (29.9%), and the difference was highly significant (p < 0.0001). Metastases in the right lobe anterior segment amounted to 279 (40.4%), and metastasis in right lobe posterior segment was 412 (59.6%), and the difference was significant. When the total number of metastatic lesions is evaluated by excluding segment I, the largest number of lesions were observed in segment VIII. The liver segments with the highest number of metastatic lesions were, respectively, VII, IV, VI, V, III, and II. In this case, the fewest metastatic lesions were observed in segment II.

CONCLUSIONS

Liver metastases of colorectal cancer are more common in the right lobe than in the left lobe. The right lobe posterior segment (segment VI) is the main target of metastases.

Liver lobe and strain differences in the activity of murine cytochrome P450 enzymes

The cytochrome P450 (CYP) enzyme superfamily is the most important enzyme system for phase I biotransformation. For toxico- and pharmacokinetic studies, use of liver-based microsomes, including those of mice, is state-of-the-art to study CYP-dependent metabolism. However, reproducibility and interpretation of these data is still very variable, partly because current testing guidelines do not cover details on organ sampling and potential liver lobe differences. Hence, we analyzed CYP activity, CYP protein content, mRNA expression of CYP1A, CYP2C, CYP2D and CYP3A isozymes, and cytochrome P450 reductase (CPR) activity of the four different liver lobes and processus papillaris of male C57BL/6J mice in comparison to whole liver. Additionally, we used whole liver of Balb/cJ and 129S1/SvImJ for strain comparison. Our data show significant differences in CYP activity, being most prominent in lobus sinister lateralis and lobus medialis, and lowest in processus papillaris. These differences were not caused by varying Cyp gene expression or CYP protein level, but partly correspond with lobe specific CPR activities. We also observed significant strain differences in CYP mRNA expression and activities with overall high activities in 129S1/SvImJ mice and low activities in Balb/cJ mice compared to C57BL/6J mice. In addition, strain specific differences in CYP2C and CYP2D activity seem to be reflected in strain dependent differences in CPR activity. In summary, our results indicate that in mice CYP activity and gene expression are strain dependent and may vary highly between liver lobes. To ensure reproducibility and comparability of different probes and studies, this should be taken into account when liver samples are collected for the analysis of CYP-dependent metabolism.

Anatomical Resections Improve Disease-free Survival in Patients With KRAS-mutated Colorectal Liver Metastases

OBJECTIVE

To investigate the potential clinical advantage of anatomical resection versus nonanatomical resection for colorectal liver metastases, according to KRAS mutational status.

BACKGROUND

KRAS-mutated colorectal liver metastases (CRLM) are known to be more aggressive than KRAS wild-type tumors. Although nonanatomical liver resections have been demonstrated as a viable approach for CRLM patients with similar oncologic outcomes to anatomical resections, this may not be the case for the subset of KRAS-mutated CRLM.

METHODS

389 patients who underwent hepatic resection of CRLM with known KRAS mutational status were identified. Survival estimates were calculated using the Kaplan-Meier method, and multivariable analysis was conducted using the Cox proportional hazards regression model.

RESULTS

In this study, 165 patients (42.4%) underwent nonanatomical resections and 140 (36.0%) presented with KRAS-mutated CRLM. Median disease-free survival (DFS) in the entire cohort was 21.3 months, whereas 1-, 3-, and 5-year DFS was 67.3%, 34.9%, and 31.5% respectively. Although there was no difference in DFS between anatomical and nonanatomical resections in patients with KRAS wild-type tumors (P = 0.142), a significant difference in favor of anatomical resection was observed in patients with a KRAS mutation (10.5 vs. 33.8 months; P < 0.001). Five-year DFS was only 14.4% in the nonanatomically resected group, versus 46.4% in the anatomically resected group. This observation persisted in multivariable analysis (hazard ratio: 0.45; 95% confidence interval: 0.27-0.74; P = 0.002), when corrected for number of tumors, bilobar disease, and intraoperative ablations.

CONCLUSIONS

Nonanatomical tissue-sparing hepatectomies are associated with worse DFS in patients with KRAS-mutated tumors. Because of the aggressive nature of KRAS-mutated CRLM, more extensive anatomical hepatectomies may be warranted.

Streamline flow of the portal vein affects the lobar distribution of colorectal liver metastases and has a clinical impact on survival

Purpose

It is believed that blood from the superior mesenteric vein and splenic vein mixes incompletely in the portal vein and maintains a streamline flow influencing its anatomic distribution. Although several experimental studies have demonstrated the existence of streamlining, clinical studies have shown conflicting results. We investigated whether streamlining of portal vein affects the lobar distribution of colorectal liver metastases and estimated its impact on survival.

Methods

Data of patients who underwent hepatectomy for colorectal liver metastases were retrospectively collected. The chi-square test was used for analyzing the distribution of metastasis. Cox analysis was used to identify risk factors of survival. Fisher exact test was used for subgroup analysis comparing hepatic recurrence.

Results

A total of 410 patients were included. The right-to-left ratio of liver metastases were 2.20:1 in right-sided colon cancer and 1.39:1 in left-sided cancer (P = 0.017). Cox analyses showed that margin < 5 mm (P < 0.001; 95% confidence interval [CI], 1.648–4.884; hazard ratio [HR], 2.837), age ≥ 60 years (P = 0.004; 95% CI, 1.269–3.641; HR, 2.149), N2 status (P < 0.001, 95% CI, 1.598–4.215; HR, 2.595), tumor size ≥ 45 mm (P = 0.014; 95% CI, 1.159–3.758; HR, 2.087) and other metastasis (P = 0.012; 95% CI, 1.250–5.927; HR, 2.722) were risk factors of survival. However, in 70 patients who underwent right hemihepatectomy for solitary metastasis, left-sided colorectal cancer was a risk factor (P = 0.019; 95% CI, 1.293–17.956; HR, 4.818), and was associated with higher recurrence than right-sided cancer (43.1% and 15.8%, respectively, P = 0.049).

Conclusion

This study showed significant difference in lobar distribution of liver metastases between right colon cancer and left colorecral cancer. Furthermore, survival of left-sided colorectal cancer was poorer than that of right-sided cancer in patients who underwent right hemihepatectomy for solitary metastasis. These findings can be helpful for clinicians planning treatment strategy.

Utility of cone-beam computed tomography in the assessment of the porto-spleno-mesenteric venous system

The common diagnostic tools available to evaluate the porto-spleno-mesenteric venous (PSMV) system provide either good hemodynamic information with limited morphological details [e.g., ultrasonography (US)] or excellent tomographic display of the anatomy with limited information about flow patterns [e.g., multidetector computed tomography (MDCT) and magnetic resonance imaging]. Although catheter-directed selective digital subtraction angiography (DSA) can provide excellent information about flow at a high temporal resolution and can generate images at a high spatial resolution, this technique is often limited by a lack of cross-sectional detail. In the assessment of the PSMV system, DSA is also limited by dilution of contrast and motion artefacts. Combining venous phase cone-beam computed tomography (CBCT) with DSA can generate high-quality tomographic data, which allows detailed evaluation of venous tributaries and flow patterns within the splenic, superior mesenteric, and inferior mesenteric venous systems individually. This enables clinicians to better understand the impact of nonobstructive resistance to flow (e.g., as in patients with cirrhosis) and obstructive resistance to flow (e.g., as in patients with thrombosis) within each system and plan treatment accordingly. In this review, we discuss the limitations of common diagnostic methods and the role venous CBCT in combination with DSA can play in assessing the PSMV system.

Comparison of Anatomical and Nonanatomical Hepatectomy for Colorectal Liver Metastasis: A Meta-Analysis of 5207 Patients

It remains unclear whether hepatectomy for colorectal liver metastasis (CRLM) should be performed as anatomical resection (AR) or nonanatomical resection (NAR). The aim of this study is to compare the short- and long-term outcomes of AR and NAR for CRLM. PubMed, Web of Science, EMBASE and the Cochrane Library were systematically searched to identify eligible studies. Twenty one studies involving 5207 patients were analyzed: 3034 (58.3%) underwent AR procedure and 2173 (41.7%) underwent NAR procedure. The results showed that overall survival (OS, hazard ratio (HR) 1.06, 95% confidence interval (CI) 0.95–1.18) and disease free survival (DFS, HR 1.11, 95% CI 0.99–1.24) did not differ significantly between AR and NAR. Duration of operation, postoperative morbidity and mortality were higher in AR than in NAR. There were no significant differences in blood loss and prevalence rate of postoperative positive margins (OR 0.79, 95% CI 0.37–1.52). Our analysis shows that AR does not seem to bring more prognostic benefits than NAR for the treatment of CRLM, and does seem to be inferior to NAR in terms of duration of operation, incidence of postoperative morbidity and mortality.

Distribution of liver metastases based on the site of primary pancreatic carcinoma

OBJECTIVES

To investigate whether the different location of pancreatic adenocarcinoma affects the lobar distribution of metastases to the liver.

METHODS

From all patients who underwent multidetector computed tomography (MDCT) examinations for staging of pancreatic adenocarcinoma in the last 4 years we selected 80 patients (42 men, 38 women; mean age, 60.56 years) with liver metastases and a pancreatic adenocarcinoma of the head (group A, 40 patients; diameter, 32.41 ± 2.28 mm) or body-tail (group B, 40 patients; diameter, 52.21 ± 2.8 mm). We analysed tumour site, diameter, vascular invasion and number of metastases in each lobe of the liver. The total number of metastases was compared between the two groups with an unpaired t-test, while Fisher's test was used to compare the number of metastases within the two lobes.

RESULTS

As expected, the number of liver metastases was higher in group B than in group A. The ratio of metastases in the right-to-left hemi-liver was 7.4:1 for group A compared with 3.3:1 for group B (p < 0.0001).

CONCLUSIONS

Although the number of liver metastases is higher in the right lobe than in the left lobe in both groups, there is a significant difference in the ratio of metastases between the right and the left hemi-liver. This supports the existence of a streamline phenomenon and a selective lobar distribution of metastases within the liver.

KEY POINTS

• Pancreatic adenocarcinoma presents with liver metastases in 40% of cases • The presence of liver metastases disqualifies the patient from curative surgery • The distribution of metastases within the liver depends on the site of pancreatic adenocarcinoma • The distribution of liver metastases is due to the streamline phenomenon.

Blood flows in tributaries of the portal vein: anatomical and angiographic studies in normal beagle dogs

Liver anatomy, particularly its vascularization, has been investigated in many studies in dogs. Knowledge of blood flow from the main tributaries of the portal vein (PV) is necessary to explain the preferential sites of secondary lesions within the liver based on the site of the initial malignant lesion. How these flows come together was established in an earlier ex vivo study. Here, we highlight in vivo the blood flows from the main PV tributaries and their distribution in the liver of normal dogs. Portographs of the main PV tributaries were obtained in seven dogs after injection of an angiographic contrast medium. After euthanasia, the livers and their portal vascularization (PV and tributaries) were extracted for a comparative corrosion cast study. Flows were demonstrated in the cranial mesenteric vein, caudal mesenteric vein and splenic vein. However, no proper flow could be distinguished for the gastroduodenal and ileocolic veins. All these tributaries primarily supply the lateral liver lobes (right or left). Most of our observations indicate that the cranial mesenteric, caudal mesenteric and splenic veins primarily supply the right lateral lobe and the caudate process of the caudate lobe and secondarily the left lateral lobe, left medial lobe and the quadrate lobe. The two other tributaries (gastroduodenal and ileocolic veins) primarily supply the right lateral lobe and the caudate process of the caudate lobe.

Relationship between primary colorectal tumour and location of colorectal liver metastases

BACKGROUND

There is conflicting evidence regarding whether streamlining of blood flow within the portal vein influences the anatomical distribution of colorectal liver metastases (CRLM). This study assesses the relationship between primary tumour location and metastases location.

METHODS

Patients were identified using a prospectively maintained database, and those with known site of primary colorectal tumour and hemiliver involvement were included. Site of metastases and segments affected were confirmed via review of the radiology reports. The location of primary colonic tumour was confirmed via review of clinical correspondence letters.

RESULTS

A total of 2364 metastases were identified in 891 patients. Of these, 379 metastases were in the right lobe and 156 in the left lobe, with 356 having bilobar disease. There was no significant relationship between the distribution of CRLM and the site of primary disease (left colon versus right colon) (P = 0.819). However, when the segmental location of the metastases was considered, there is a statistically significant difference between the number of right-sided CRLM compared with left-sided CRLM (P < 0.001).

CONCLUSIONS

Right-sided CRLM is more likely regardless of the primary location. Portal streaming may have an effect, although the natural anatomical 'angulation', particularly of the left portal vein branch is more likely to play a role.

Are hepatic portal venous system components distributed equally in the liver? A multidetector computerized tomography study

OBJECTIVE

We aimed to evaluate the relationships between the splenic index, right and left hepatic lobe volumes, diameters of splenic vein (SV), superior mesenteric vein (SMV) and the portal vein (PV) by Multidetector Computerized Tomography (MDCT). We also investigated indirect signs of portal venous flow pattern using these parameters.

MATERIAL AND METHODS

Following their contrast thoracoabdominal and abdominal 64-MDCT examinations, the images of 100 cases (61 males and 39 females) were evaluated retrospectively. For each case, the splenic index, total hepatic volume, left and right hepatic volumes were calculated on the post-contrast portal venous phase (50(th) sec) images. Spearman correlation tests were carried out with the purpose of determining the relationships between the variables. Statistical significance level was set at p<0.005.

RESULTS

A statistically significant relation was demonstrated between the diameter of the SMV and right hepatic lobe volume (p<0.0001), and according to Pearson's correlation analysis, a positive correlation of medium strength (r=0.36) was observed. A positive correlation was demonstrated between the diameter of the splenic vein and left hepatic lobe volume (r=0.36). Statistically significant relation between the diameters of the splenic vein and right hepatic lobe was not observed (p=0.62). A strong correlation between the left hepatic lobe volume and the splenic index (r=0.556) was observed.

CONCLUSION

We observed a positive correlation and a significant relation between the diameter of the SMV and the right hepatic lobe, and a relation between the splenic vein and splenic index and both hepatic lobes. We believe that this situation is related to the streamline flow in the portal vein, and as demonstrated in the literature, the flow in the SMV is directed at the right lobe, whereas the splenic vein empties into the liver homogenously. Our study is the first study in the literature performed by multidetector CT, which is a technique that reveals the relations between the streamline flow in the portal vein, the splenic index and the hepatic lobe volumes.

Appraisal of 1 cm hepatectomy margins for intrahepatic micrometastases in patients with colorectal carcinoma liver metastasis

BACKGROUND

This study sought to clarify the distribution of intrahepatic micrometastases and elucidate an adequate hepatectomy margin for colorectal carcinoma liver metastases.

METHODS

Intrahepatic micrometastases in resected specimens from 90 patients who underwent hepatectomy for colorectal carcinoma liver metastases were examined retrospectively. Intrahepatic micrometastases were defined as microscopic lesions spatially separated from the gross tumor. Distances from these lesions to the hepatic tumor borders were measured histologically, and the density of intrahepatic micrometastases (number of lesions/mm(2)) calculated relative to the advancing tumor border in a zone <1 cm from the border (close) or >/=1 cm away (distant). Median follow-up time was 127 months.

RESULTS

A total of 294 intrahepatic micrometastases were detected in 52 (58%) patients; 95% of these occurred in the close zone. The density of intrahepatic micrometastases was significantly higher in the close zone (mean 74.8 x 10(-4 ) lesions/mm(2)) than in the distant zone (mean 7.4 x 10(-4 ) lesions/mm(2); P < 0.001). Hepatectomy margin status was positive by 0 cm in 10 patients or negative by <1 cm in 51, and by >/=1 cm in 29 patients. The median survival times were 18, 33, and 89 months in patients with hepatectomy margins 0 cm, <1 cm, and >/=1 cm, respectively. Hepatectomy margin status independently influenced survival (P < 0.001) and disease-free survival (P < 0.001).

CONCLUSION

The currently recommended >/=1 cm hepatectomy margin should remain the goal for resections of colorectal carcinoma liver metastases, based on the distribution of intrahepatic micrometastases and survival risk.

Location of liver metastases reflects the site of the primary colorectal carcinoma

OBJECTIVE

The present study was designed to investigate whether the different venous return of different locations of colorectal carcinomas affects the lobar distribution of metastases to the liver, due to the "streaming" within the portal vein.

MATERIAL AND METHODS

The site of the primary colorectal carcinoma was divided into the right- and left hemicolon according to the different venous drainage via the superior and the inferior mesenteric/splenic vein. Both groups were analyzed for the distribution of the metastases in the liver. The anatomic site of the liver metastases was detected by intraoperative exploration and differentiated between the two lobes using the Cantlie line.

RESULTS

Out of a total of 178 patients, 109 men and 69 women with 264 metastases were eligible for the study. The ratio of metastases in the right and left hemiliver was 3.6:1 for 35 right-sided primary tumors (p=0.002) compared with 2.1:1 for 143 left-sided primary tumors (p=NS). No significant differences were evident for the sub-analysis of involved liver segments.

CONCLUSIONS

The results of our study support the existence of the "streaming" effect in the portal vein. Right-sided colon carcinomas predominantly involve the right hemiliver, while left-sided colon carcinomas involve the liver homogeneously, considering the size ratio of the right to left liver lobe, which is about 2:1. Knowledge of streaming may help us to understand the spread of abdominal malignancies and may provide a reference concerning the possible primary site depending on metastatic distribution in the liver.

Intrahepatic lymphatic invasion independently predicts poor survival and recurrences after hepatectomy in patients with colorectal carcinoma liver metastases

BACKGROUND

D2-40 monoclonal antibody immunoreactivity is specific for lymphatic endothelium and therefore provides a marker of lymphatic invasion. We hypothesized that intrahepatic lymphatic invasion reflects the nodal status of colorectal carcinoma liver metastases and may function as an adverse prognostic factor.

METHODS

A retrospective analysis of 105 consecutive patients who underwent resection for colorectal carcinoma liver metastases was conducted. Intrahepatic lymphatic invasion was declared when either single tumor cells or cell clusters were clearly visible within vessels that showed immunoreactivity for D2-40 monoclonal antibody. The median follow-up time was 124 months.

RESULTS

Of 105 patients, 13 were classified as having intrahepatic lymphatic invasion. All tumor foci of intrahepatic lymphatic invasion were detected within the portal tracts. Intrahepatic lymphatic invasion was significantly associated with hepatic lymph node involvement (P = 0.039). Survival after resection was significantly worse in patients with intrahepatic lymphatic invasion (median survival time of 13 months; cumulative five-year survival rate of 0%) than in patients without (median survival time of 40 months; cumulative five-year survival rate of 41%; P < 0.0001). Patients with intrahepatic lymphatic invasion also showed decreased disease-free survival rates (P < 0.0001). Intrahepatic lymphatic invasion thus independently affected both survival (relative risk, 7.666; 95% confidence interval, 3.732-15.748; P < 0.001) and disease-free survival (relative risk, 4.112; 95% confidence interval, 2.185-7.738; P < 0.001).

CONCLUSIONS

Intrahepatic lymphatic invasion is associated with hepatic lymph node involvement and is an adverse prognostic factor in patients with colorectal carcinoma liver metastases.

Different concentrations of I-123 MIBG and In-111 pentetreotide in the two main liver lobes in children: persisting regional functional differences after birth?

PURPOSE

At examinations in children with I-123 metaiodobenzylguanidine or with In-111 pentetreotide using SPECT, we have observed a different distribution of the radiopharmaceuticals between the left and right main liver lobes. This phenomenon was studied in retrospect from clinical examinations.

PATIENTS AND METHODS

Seventeen children (mean age, 51 months; range, 11-150 months) with neuroblastoma or ganglioneuroma examined with both radiopharmaceuticals within 1 week using SPECT were assessed. There was no history of liver disease and all liver lobes showed uniform activity distribution. Simultaneous radiologic examinations were all normal with regard to the liver. No child with a pathologic liver chemistry test was included. The activity ratios between the left and right main liver lobes were calculated from transverse tomographic sections.

RESULTS

The mean left:right lobar activity ratio for I-123 metaiodobenzylguanidine was 1.26+/-0.12 (null hypothesis=1.00; P<0.001) and for In-111 pentetreotide 0.88+/-0.06 (null hypothesis=1.00; P<0.001). There was no age-dependent distribution of the tracers. The correlation between the tracer uptake of the different liver lobes was very weak.

CONCLUSION

A functional difference between the 2 main liver lobes in utero is believed to reflect differences of the vascular supply. The current findings indicate a persisting functional heterogeneity of the liver after birth not caused by perfusion differences. A relatively higher uptake of I-123 MIBG and a lower uptake of In-111 pentetreotide of the left liver lobe are normal findings.

Pre- and postprandial alterations of portal venous flow: Evaluation with single breath-hold three-dimensional half-fourier fast spin-echo MR imaging and a selective inversion recovery tagging pulse

PURPOSE

To evaluate the influence of food intake on portal flow using unenhanced magnetic resonance imaging (MRI).

MATERIALS AND METHODS

The study population included 29 healthy subjects. A selective inversion recovery tagging pulse was used on the superior mesenteric vein (SMV) and splenic vein (SpV) to study the correlation of tagged blood in the portal vein (PV). MRI was performed before and 60-90 min after a meal.

RESULTS

The flow signal from the SMV increased in 97% of the subjects after the meal. Before the meal the portal flow was dominated by flow from the SpV in 59% of the subjects, while it was dominated by flow from the SMV in 76% of the subjects after the meal. The most common distribution pattern of the flow signal from the SpV before the meal was in the central part of the main PV (55%), while it was in the left side (45%) after the meal. The most common distribution pattern of the flow signal from the SMV was in the bilateral sides of the main PV both before and after the meal (62%).

CONCLUSION

This technique shows potential for evaluating pre- and postprandial alterations of flow from the SpV and SMV in the PV under physiological conditions.

Different concentrations of various radiopharmaceuticals in the two main liver lobes: a preliminary study in clinical patients

BACKGROUND

At clinical scintigraphic examinations of the abdomen using single photon emission computed tomography (SPECT), we have observed a different distribution between the left and right main liver lobes of various radiopharmaceuticals. This was studied retrospectively in clinical patients.

METHODS

Examinations with [123I]-metaiodobenzylguanidine MIBG; (n=19), a 99mTc-labelled monoclonal antibody against granulocytes (n=18), and 111In-pentetreotide (n=26) were assessed. There was no known history of, or risk factor for liver disease, and all lobes showed a uniform activity distribution. Twenty healthy volunteers underwent consecutive examinations with 99mTc-dimethyliminodiacetic acid (HIDA). The activity ratios between the left and right main liver lobes were calculated from the transverse tomographic (SPECT) sections.

RESULTS

The left: right lobar activity ratio for [123I]-MIBG was (mean+/-SD) 1.25+/-0.21 (null hypothesis=1.00; P<0.001); for the antibody, acquisition after 3-5 h was 0.98+/-0.06 (NS) and after 20-24 h, 0.99+/-0.11 (NS); for 111In-pentetreotide, 0.90+/-0.09 (P<0.001); for 99mTc-HIDA, immediate acquisition, 0.68+/-0.12 (P<0.001) and acquisition at 7 min, 0.66+/-0.12 (P<0.001).

CONCLUSIONS

The differences in tracer uptake between the liver lobes cannot be caused only by differences in blood flow. One explanation of the higher uptake of [123I]-MIBG by the left lobe may be a greater presence of catecholamines and a higher sympathetic nerve density in this liver portion. Consequently, there may be a functional difference between the two main liver lobes.

Detection of disseminated tumour cells in the liver of colorectal cancer patients

AIMS

The aim of this study was to assess the incidence and lobar distribution of three surrogate tumour cell markers in biopsies from both liver lobes.

PATIENTS AND METHODS

This study comprised 189 patients for whom DNA and/or RNA was available from both liver lobes and who showed at least one positive marker in one liver lobe. Detection of cytokeratin 20 (CK20) and guanylylcyclase C (GCC) was performed by nested reverse transcription-PCR. For detection of K-ras mutations in codons 12 and 13, a PCR-restriction-fragment-length-polymorphism assay was used.

RESULTS

The incidence of all markers and their combinations was higher in the smaller left lobe than in the larger right lobe (CK20: 62 vs 38%; GCC: 52 vs 48%; K-ras: 61 vs 39%; CK20+GCC: 61 vs 39%; CK20+GCC and/or K-ras: 61 vs 39%). The marker incidence in the two liver lobes was independent from the location of the respective primary colorectal carcinoma.

CONCLUSIONS

The markers CK20, GCC, and K-ras indicating cells shed from the primary CRC were detected more often individually and in combination in biopsies from the smaller left lobe than from the larger right lobe. The site of the primary tumour did not influence the marker incidence in both liver lobes.

Immunohistochemically detected hepatic micrometastases predict a high risk of intrahepatic recurrence after resection of colorectal carcinoma liver metastases

BACKGROUND

Hepatic metastases from colorectal carcinoma frequently recur after resection and hepatic micrometastases most likely are important in the development of such recurrences. The objectives of the current study were to assess the feasibility of the immunohistochemical detection of hepatic micrometastases from colorectal carcinoma and to determine their clinical significance.

METHODS

Fifty-three patients underwent curative hepatic resection for colorectal carcinoma metastases. Multiple tissue sections were cut from the advancing margin of the largest hepatic metastasis in each patient and were stained with an antibody against cytokeratin-20 to detect hepatic micrometastases, which were defined as discrete microscopic cancerous lesions surrounding the dominant metastasis.

RESULTS

Normal hepatocytes and intrahepatic bile duct epithelia stained negative for cytokeratin-20 in all patients, whereas the largest hepatic tumors stained positive in 46 patients (86.8%). Among the 46 patients with hepatic tumors that were positive for cytokeratin-20, hepatic micrometastases were found immunohistochemically in 32 patients (69.6%). The presence of hepatic micrometastases was associated with a larger number of macroscopic hepatic metastases (P = 0.047) and patients with hepatic micrometastases were found to demonstrate a higher probability of intrahepatic recurrence (P = 0.003) compared with those patients without hepatic micrometastases. In addition, patients with hepatic micrometastases demonstrated a worse survival (10-year survival rate of 21.9%) compared with those patients without hepatic micrometastases (10-year survival rate of 64.3%) (P = 0.017).

CONCLUSIONS

Immunohistochemical detection of hepatic micrometastases is feasible in patients with colorectal carcinoma liver metastases. Hepatic micrometastasis indicates widespread hepatic involvement and thus predicts an increased risk of intrahepatic recurrence after hepatic resection and a poorer patient prognosis.

Distribution of colorectal liver metastases in patients referred for hepatic resection

BACKGROUND

There is a perception that streamline flow of blood in the portal vein may influence the anatomic distribution of liver metastases, depending on the site of the primary tumor. It has previously been reported that cancers arising in the right colon are distributed to the right lobe of the liver 10 times more commonly than to the left lobe, whereas liver metastases from tumors arising from the left colon and rectum are believed to be distributed homogenously.

METHODS

Data were collected prospectively on the anatomic site of hepatic metastases in 207 patients with colorectal metastases referred for consideration for surgery. Anatomic site was established by a combination of computed tomography scanning and either laparoscopic or intraoperative ultrasonography. The site of the primary tumor was known in all cases.

RESULTS

A total of 708 metastases were identified, of which 67% were in the right hemiliver and 33% were in the left. The ratio of involvement of the right and left hemilivers by metastases arising from right colon tumors was 2. 02:1 and for left colon tumors 2.1:1. When patients with unilobar disease only were considered, the ratio of involvement of the right and left hemilivers increased to 2.9:1, but again no difference was evident that depended on the site of the primary tumor.

CONCLUSIONS

This study could not find any evidence to support a differential pattern of metastasis within the liver dependent on the location of the primary colorectal carcinoma.

Evidence that metastasis is less common in cirrhotic than normal liver: a systematic review of post-mortem case-control studies

BACKGROUND

It has been hypothesized that the cirrhotic liver is afforded protection against metastasis. The evidence has been examined and the plausibility of such a phenomenon is reviewed.

METHODS

A systematic literature review was conducted with analysis of combined data from post-mortem case-control studies.

RESULTS

Overall, the crude rate of metastasis to normal liver was 37.3 per cent, while the rate to cirrhotic liver was 23.7 per cent. The Mantel-Haenszel (MH) fixed-effects estimate of the odds ratio was 0. 47 (95 per cent confidence interval (c.i.) 0.41-0.53; chi2 = 136, 11 d.f., P < 0.001). The DerSimonian-Laird (DL) random-effects estimation of the odds ratio was 0.42 (95 per cent c.i. 0.31-0.58; chi2 = 28, 1 d.f., P < 0.001). For tumours arising within the distribution of the portal vein, the crude rate of metastasis to normal liver was 47.6 per cent, whereas the rate to cirrhotic liver was 29.8 per cent. The MH estimate of the odds ratio was 0.45 (95 per cent c.i. 0.37-0.54; chi2 = 68.2, 5 d.f., P < 0.001). The DL pooled odds ratio was 0.44 (95 per cent c.i. 0.28-0.70; chi2 = 12.3, 1 d.f., P < 0.001). The MH and DL pooled estimates of the odds ratio were similar for groups of patients from the East (Japan) and the West (Europe and the USA).

CONCLUSION

The post-mortem evidence reviewed suggests that the likelihood of metastasis to the cirrhotic liver is lower than that to normal liver. The degree of protection for tumours arising from within the distribution of the portal vein is neither greater nor less than it is overall. Eastern and Western populations appear to have a similar degree of risk reduction. The differences noted were significant on testing in the meta-analysis, but confounding bias accounting for these differences has not been excluded.

Heterogeneous suppression of experimentally induced colon cancer metastasis in rat liver lobes by inhibition of extracellular cathepsin B

Metastatic rat colon cancer cells but not normal rat hepatocytes showed activity of cathepsin B on their plasma membranes. Activity was visualized in living cells with a new fluorogenic substrate, [Z-Arg]2-cresyl violet, and confocal microscopy. When these cancer cells were injected into the portal vein of rats, the animals developed tumors in the liver in a heterogeneous fashion. Three- to four-fold more tumors were found in the small caudate lobe than in the other three large lobes of the liver. Oral treatment with a selective water-soluble inhibitor of extracellular cathepsin B, Mu-Phe-homoPhe-fluoromethylketone, resulted in 60% reduction of the number of tumors and 80% reduction of the volume of tumors in the three large lobes whereas tumor development was not affected in the small caudate lobe. This study supports the conclusions that (a) extracellular cathepsin B plays a crucial but complex role in liver colonisation by rat colon carcinoma cells in vivo, (b) its selective inhibition suppresses tumor growth heterogeneously in the liver and (c) the caudate lobe of the liver is a relatively large risk factor for tumor development.