Intraoperative Liver Ultrasound Still Affects Surgical Strategy for Patients with Colorectal Metastases in the Modern Era

Augmented Reality and Image-Guided Robotic Liver Surgery

Artificial intelligence makes surgical resection easier and safer, and, at the same time, can improve oncological results. The robotic system fits perfectly with these more or less diffused technologies, and it seems that this benefit is mutual. In liver surgery, robotic systems help surgeons to localize tumors and improve surgical results with well-defined preoperative planning or increased intraoperative detection. Furthermore, they can balance the absence of tactile feedback and help recognize intrahepatic biliary or vascular structures during parenchymal transection. Some of these systems are well known and are already widely diffused in open and laparoscopic hepatectomies, such as indocyanine green fluorescence or ultrasound-guided resections, whereas other tools, such as Augmented Reality, are far from being standardized because of the high complexity and elevated costs. In this paper, we review all the experiences in the literature on the use of artificial intelligence systems in robotic liver resections, describing all their practical applications and their weaknesses.

Intraoperative (Contrast-Enhanced) Ultrasound Has the Highest Diagnostic Accuracy of Any Imaging Modality in Resection of Colorectal Liver Metastases

AIM

Defining sensitivity, specificity, diagnostic accuracy for detection of colorectal liver metastases in imaging compared to intraoperative assessment. Defining a cutoff, where accuracy of detection is impaired.

METHODS

Prospective single-institution clinical trial (clinicaltrials.gov: NCT01522209). Patients underwent CEUS, MDCT, and 3 Tesla EOB-MRI within 2 weeks preoperatively. Intraoperative palpation, IOUS, and CEIOUS were performed. A patient and lesion-based database was analyzed for accuracy of detection of CEUS, CT, MRI, and Palp/IOUS/CEIOUS combined read. Histology was standard of reference.

RESULTS

Forty-seven high tumor load (mean 5, 4 lesions) patients were analyzed. Histopathology confirmed 264 lesions (245 malignant: 19 benign). Accuracy for detection of all lesions: CEUS 63%, CT 71%, MRI 92%, and PALP/IOUS/CEIOUS 98%. ROC analysis for lesion size showed severe impairment of accuracy in lesion detection smaller than 5mm. Intraoperative imaging was not impaired by lesion size. Patient-based analysis revealed a change of resection plan after IOUS/CEIOUS in 35% of patients.

CONCLUSION

At 5-mm lesion size, preoperative imaging shows a drop in accuracy of detection. In patients with multiple lesions, addition of MRI to MDCT seems useful. Accuracy of intraoperative ultrasound is not impacted by lesion size and should be mandatory. CEIOUS can improve intraoperative decision-making.

TRIAL REGISTRATION

Study registered with clinicaltrials.gov : NCT01522209.

The Italian Consensus on minimally invasive simultaneous resections for synchronous liver metastasis and primary colorectal cancer: A Delphi methodology

At the time of diagnosis synchronous colorectal cancer, liver metastases (SCRLM) account for 15-25% of patients. If primary tumour and synchronous liver metastases are resectable, good results may be achieved performing surgical treatment incorporated into the chemotherapy regimen. So far, the possibility of simultaneous minimally invasive (MI) surgery for SCRLM has not been extensively investigated. The Italian surgical community has captured the need and undertaken the effort to establish a National Consensus on this topic. Four main areas of interest have been analysed: patients' selection, procedures, techniques, and implementations. To establish consensus, an adapted Delphi method was used through as many reiterative rounds were needed. Systematic literature reviews were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses instructions. The Consensus took place between February 2019 and July 2020. Twenty-six Italian centres participated. Eighteen clinically relevant items were identified. After a total of three Delphi rounds, 30-tree recommendations reached expert consensus establishing the herein presented guidelines. The Italian Consensus on MI surgery for SCRLM indicates possible pathways to optimise the treatment for these patients as consensus papers express a trend that is likely to become shortly a standard procedure for clinical pictures still on debate. As matter of fact, no RCT or relevant case series on simultaneous treatment of SCRLM are available in the literature to suggest guidelines. It remains to be investigated whether the MI technique for the simultaneous treatment of SCRLM maintain the already documented benefit of the two separate surgeries.

Local control of hepatocellular carcinoma and colorectal liver metastases after surgical microwave ablation without concomitant hepatectomy

PURPOSE

Microwave ablation (MWA) is an accepted technique in the multimodal treatment of hepatocellular carcinoma (HCC) and colorectal liver metastases (CRLM). Study endpoints were to evaluate the local efficacy of surgical MWA in selected patients with oligonodular disease without the combination of liver resection to allow a clear interpretation of the follow-up imaging and compare it to the results on percutaneous MWA available in the literature.

METHODS

Consecutive MWA-only procedures performed between May 2013 and May 2018 for HCC and CRLM with free-hand ultrasound guidance were identified. MWA systems with 2450 MHz were used. Incomplete ablation (IA) was defined as residual disease within 1 cm of the ablation site at the first post-ablation imaging and local recurrence (LR) as the presence of disease after at least one tumor-free imaging.

RESULTS

A total of 70 tumors in 47 patients were treated with 46 laparoscopic and 1 open procedures. Each patient had no more than 3 tumors, and median size of the lesions was 15 mm (IQR: 10-22). After a median follow-up of 26 months (IQR: 12-40), IA rate was 8.6% and LR rate was 29.4%. Multivariable analysis showed that vascular proximity (OR = 3.4; 95% CI = 1.26-9.22; p=0.016) was the only significant predictor of the combined outcome IA or LR.

DISCUSSION

In the present study, after mostly laparoscopic MWA, LR was higher than the rates available in the literature for percutaneous MWA of HCC but lower than in the limited studies analyzing isolated percutaneous MWA of liver metastases. Future developments may help establish the role of each therapeutic modality per tumor, in order to improve the outcomes.

Narrow-band Imaging Examination of Microvascular Architecture of Subcapsular Hepatic Tumors

BACKGROUND

Intraoperative ultrasonography is the golden standard method for evaluation of liver tumors during hepatectomy. However, in laparoscopic surgery, accurate assessment of tumors may be difficult, particularly if the lesion is located nearby the liver surface because of the challenges in handling the intraoperative ultrasound and the lack of tactile sensation. In this study, we demonstrate the preliminary results of examining the microvascular architecture of subcapsular hepatic tumors using laparoscopic narrow-band imaging (NBI) to distinguish between malignant and benign tumors.

MATERIALS AND METHODS

Thirty-five lesions were examined by NBI during laparoscopic hepatectomy for the presence of abnormal microvasculature on the liver surface in relation to hepatic tumors from January 2016 to August 2018. The microvascular findings were correlated with tumor localization and pathological diagnosis.

RESULTS

The 35 examined nodules included 11 hepatocellular carcinoma, 18 colorectal liver metastasis, and six benign nodules. The mean tumor diameter was 26.3 (3-70) mm, and the distance from the liver surface to the tumor was 0.5 (0-5) mm. Microvessels on the liver surface were clearly visualized by NBI, consistent with malignant tumor localization. The tumors were thoroughly examined for the presence of three pathological microvascular features (enlargement, tortuosity, and heterogeneity). Abnormal microvascular patterns were found in 90.9% of hepatocellular carcinoma and 77.8% of colorectal liver metastasis, whereas neither normal sites nor benign lesions displayed microvascular abnormality.

CONCLUSIONS

This study suggests that observing the microvessel image on the liver surface by NBI could be useful in tumor localization and differentiation between benign and malignant lesions.

Current role of intraoperative ultrasonography in hepatectomy

Hepatectomy had a high mortality rate in the previous decade because of inadequate techniques, intraoperative blood loss, liver function reserve misdiagnoses, and accompanying postoperative complications. However, the development of several modalities, including intraoperative ultrasonography (IOUS), has made hepatectomy safer. IOUS can provide real-time information regarding the tumor position and vascular anatomy of the portal and hepatic veins. Systematic subsegmentectomy, which leads to improved patient outcomes, can be performed by IOUS in open and laparoscopic hepatectomy. Although three-dimensional (3D) computed tomography and gadoxetic acid-enhanced magnetic resonance imaging have been widely used, IOUS and contrast-enhanced IOUS are important modalities for risk analyses and making decisions regarding resectability and operative procedures because of the vital anatomical information provided and high sensitivity for liver tumors, including "disappearing" liver metastases. Intraoperative color Doppler ultrasonography can be used to delineate the vascular anatomy and evaluate the blood flow volume and velocity in hepatectomy patients and recipients of deceased- and living-donor liver transplantation after vessel reconstruction and liver positioning. For liver surgeons, IOUS is an essential technique to perform highly curative hepatectomy safely, although recent advances have also been made in virtual modalities, such as real-time virtual sonography with 3D visualization.

Routine Intraoperative Ultrasound for the Detection of Liver Metastases during Resection of Primary Colorectal Cancer - A Systematic Review

During the discovery of ColoRectal Cancer (CRC), 20% to 30% of patients have synchronous liver metastases. Ten to 30% of patients have non-evidence of Liver Metasteses (LM) following preoperative imaging such as Contrast-Enhanced Ultrasound (CE-US), multi-slice Contrast-Enhanced Computed Tomography (CE-CT), Contrast-Enhanced Magnetic Resonance Imaging (CE-MRI), and Positron Emission Tomography-Computed Tomography (PET-CT). Today, IntraOperative UltraSound (IOUS) in open surgery and Laparoscopic UltraSound (LUS) in laparoscopic or robotic surgery are considered the "gold standard" for detecting liver metastases. The object of this review is to demonstrate the higher sensitivity and specificity of IOUS and LUS in the detection rate of liver metastases.

Comparison of laparoscopic ultrasound and liver-specific magnetic resonance imaging for staging colorectal liver metastases

BACKGROUND

Intraoperative liver ultrasound appears superior to liver-specific contrast-enhanced magnetic resonance imaging (MRI) to stage colorectal liver metastases (CRLMs). Most of the data come from studies on open surgery. Laparoscopic ultrasound (LUS) is technically demanding and its reliability is poor investigated. Aim of the study was to assess the accuracy of LUS staging for CRLMs compared to MRI.

METHODS

All patients with CRLMs scheduled for laparoscopic liver resection (LLR) between 01/2010 and 06/2019 who underwent preoperative MRI were considered for the study. LUS and MRI performance was compared on a patient by patient basis. Reference standards were final pathology and 6 months follow-up results.

RESULTS

Amongst 189 LLR for CRLMs, 146 met inclusion criteria. Overall, 391 CRLMs were preoperatively detected by MRI. 24 new nodules in 16 (10.9%) patients were found by LUS and resected. Median diameter of new nodules was 5.5 mm (2-10 mm) and 10 (41.6%) were located in the hepatic dome. Pathology confirmed 17 newly detected malignant nodules (median size 4 mm) in 11 (7.5%) patients. Relationships between intrahepatic vessels and tumours differed between LUS and MRI in 9 patients (6.1%). Intraoperative surgical strategy changed according LUS findings in 19 (13%) patients, requiring conversion to open approach in 3 (15.8%) of them. The sensitivity of LUS was superior to MRI (93.1% vs 85.6% whilst specificity was similar (98.6% MRI vs 96.5% LUS).

CONCLUSIONS

Laparoscopic liver ultrasound improves liver staging for CRLMs compared to liver-specific MRI.

Decision-making based on 3D printed models in laparoscopic liver resections with intraoperative ultrasound: a prospective observational study

OBJECTIVES

The aim of this study was to evaluate impact of 3D printed models on decision-making in context of laparoscopic liver resections (LLR) performed with intraoperative ultrasound (IOUS) guidance.

METHODS

Nineteen patients with liver malignances (74% were colorectal cancer metastases) were prospectively qualified for LLR or radiofrequency ablation in a single center from April 2017 to December 2018. Models were 3DP in all cases based on CT and facilitated optical visualization of tumors' relationships with portal and hepatic veins. Planned surgical extent and its changes were tracked after CT analysis and 3D model inspection, as well as intraoperatively using IOUS.

RESULTS

Nineteen patients were included in the analysis. Information from either 3DP or IOUS led to changes in the planned surgical approach in 13/19 (68%) patients. In 5/19 (26%) patients, the 3DP model altered the plan of the surgery preoperatively. In 4/19 (21%) patients, 3DP independently changed the approach. In one patient, IOUS modified the plan post-3DP. In 8/19 (42%) patients, 3DP model did not change the approach, whereas IOUS did. In total, IOUS altered surgical plans in 9 (47%) cases. Most of those changes (6/9; 67%) were caused by detection of additional lesions not visible on CT and 3DP.

CONCLUSIONS

3DP can be helpful in planning complex and major LLRs and led to changes in surgical approach in 26.3% (5/19 patients) in our series. 3DP may serve as a useful adjunct to IOUS.

KEY POINTS

• 3D printing can help in decision-making before major and complex resections in patients with liver cancer. • In 5/19 patients, 3D printed model altered surgical plan preoperatively. • Most surgical plan changes based on intraoperative ultrasonography were caused by detection of additional lesions not visible on CT and 3D model.

Intraoperative Ultrasound Staging for Colorectal Liver Metastases in the Era of Liver-Specific Magnetic Resonance Imaging: Is It Still Worthwhile?

Background

To assess the efficacy of intraoperative ultrasound (IOUS) compared with liver-specific magnetic resonance imaging (MRI) in patients with colorectal liver metastases (CRLMs).

Methods

From January 2010 to December 2017, 721 patients underwent MRI as a part of preoperative workup within 1 month before hepatectomy and were considered for the study. Early intrahepatic recurrence (relapse at cut surface excluded) was assessed 6 months after the resection and was considered as residual disease undetected by IOUS and/or MRI. IOUS and MRI performance was compared on a patient-by-patient basis. Long-term results were also studied.

Results

A total of 2845 CRLMs were detected by MRI, and the median number of CRLMs per patient was 2 (1–31). Preoperative chemotherapy was administered in 489 patients (67.8%). In 177 patients, 379 new nodules were intraoperatively found and resected. Among 379 newly identified nodules, 317 were histologically proven CRLMs (11.1% of entire series). The median size of new CRLMs was 6 ± 2.5 mm. Relationships between intrahepatic vessels and tumors differed between IOUS and MRI in 128 patients (17.7%). The preoperative surgical plan was intraoperatively changed for 171 patients (23.7%). Overall, early intrahepatic recurrence occurred in 8.7% of cases. To assess the diagnostic performance, 24 (3.3%) recurrences at the cut surface were excluded; thus, 5.4% of early relapses were considered for analysis. The sensitivity of IOUS was superior to MRI (94.5% vs 75.1%), while the specificity was similar (95.7% vs 95.9%). Multivariate analysis at the hepatic dome or subglissonian and mucinous histology revealed predictive factors of metastases missing at MRI. The 5-year OS (52.1% vs 37.8%, p=0.006) and DF survival (45.1% vs 33%, p=0.002) were significantly worse among patients with new CRLMs than without.

Conclusions

IOUS improves staging in patients undergoing resection for CRLMs even in the era of liver-specific MRI. Intraoperative detection of new CRLMs negatively affects oncologic outcomes.

A Mechatronic Platform for Computer Aided Detection of Nodules in Anatomopathological Analyses via Stiffness and Ultrasound Measurements

This study presents a platform for ex-vivo detection of cancer nodules, addressing automation of medical diagnoses in surgery and associated histological analyses. The proposed approach takes advantage of the property of cancer to alter the mechanical and acoustical properties of tissues, because of changes in stiffness and density. A force sensor and an ultrasound probe were combined to detect such alterations during force-regulated indentations. To explore the specimens, regardless of their orientation and shape, a scanned area of the test sample was defined using shape recognition applying optical background subtraction to the images captured by a camera. The motorized platform was validated using seven phantom tissues, simulating the mechanical and acoustical properties of ex-vivo diseased tissues, including stiffer nodules that can be encountered in pathological conditions during histological analyses. Results demonstrated the platform’s ability to automatically explore and identify the inclusions in the phantom. Overall, the system was able to correctly identify up to 90.3% of the inclusions by means of stiffness in combination with ultrasound measurements, paving pathways towards robotic palpation during intraoperative examinations.

Intraoperative ultrasound for the colorectal surgeon: current trends and barriers

Up to two thirds of patients diagnosed with colorectal cancer (CRC) develop colorectal liver metastases (CRLMs) and one quarter of patients present with synchronous metastases. Early detection of CRLM widens the scope of potential treatment. Surgery for CRLM offers the best chance of a cure. Current preoperative staging of CRC relies on computerized tomography and magnetic resonance imaging. Intraoperative ultrasound (IOUS) scans and contrast-enhanced IOUS (CE-IOUS) have been demonstrated to detect additional metastases not seen on routine preoperative imaging. IOUS is not widely used by colorectal surgeons during primary resection for CRC. Confident use of IOUS/CE-IOUS during primary resection of CRC may improve decision-making by providing the most sensitive form of liver staging even when compared with magnetic resonance imaging. This may be particularly important in the era of laparoscopic resections, where the colorectal surgeon loses the opportunity to palpate the liver. There are several implied barriers to the routine use of IOUS/CE-IOUS by colorectal surgeons. These include time pressure, familiarity with techniques, a perceived learning curve, cost implications and limitation of the modality due to operator variations. Inclusion of IOUS in the training of colorectal surgeons and further investigation of potential benefits of IOUS/CE-IOUS could potentially reduce these barriers, enabling usage during primary resection for CRC to become more widespread.

Current technical aspects of oncological hepatic surgery

BACKGROUND

With the recent advances in oncological hepatic surgery, major liver resections became more widely utilized procedures. The era of modern hepatic surgery witnessed improvements in patients care in preoperative, intraoperative and postoperative aspects. This significantly improved surgical outcomes regarding morbidity and mortality. This review article focuses on the recent advances in oncological hepatic surgery.

DATA SOURCES

This review includes only data from peer-reviewed articles and journals. PubMed database was utilized as the primary source of the supporting literature to this review article on the latest advances in oncological hepatic surgery. Comprehensive and high sensitivity search strategies were performed to search related studies exhaustively up till June 2016. We critically and independently assessed over 50 recent publications written on this topic according to the selection criteria and quality assessment standard. We paid particular attention to the studies published in high impact journals that address the use of the surgical techniques mentioned in the articles in well-known institutions.

RESULTS

Among all utilized approaches aiming at the preoperative assessment of the liver function, Child-Turcotte-Pugh classification remains the most reliable tool correlating with survival outcome. Although the primary radiological tools including ultrasonography, computed tomography and magnetic resonance imaging remain on top of the menu of tests utilized in assessment of focal hepatic lesions, intraoperative ultrasonography projects to be a powerful additional tool in terms of sensitivity and specificity compared to the other conventional techniques in assessment of the liver in the operative setting, a procedure that can change the surgical strategy in 27.2% of the cases and consequently improve the oncological surgical outcome. In addition to the conventional surgical techniques of liver resection and portal vein embolization, associating liver partition and portal vein ligation for staged hepatectomy "ALPPS" projects to be an alternative option in patients with marginally resectable tumors with an inadequate size of future liver remnant with an accepted surgical oncological outcome.

CONCLUSIONS

Considering the clinicopathological nature of hepatic lesions, the comprehensive assessment and proper choice of the liver resection technique in highly selected patients is associated with improved surgical oncological outcome. Patients with underlying marginal future liver remnant volumes can now safely benefit from a wider range of surgical intervention, a breakthrough that significantly improved morbidity and mortality in this group of patients.

Diagnostic accuracy of confocal laser endomicroscopy for the characterization of liver nodules

OBJECTIVES

Probe-based confocal laser endomicroscopy (pCLE) is a promising new imaging technique enabling in-vivo analysis of tissues at the cellular level, in real time. The aim of the present study was to prospectively evaluate the feasibility and accuracy of indocyanine green-aided pCLE for the diagnosis of malignant liver nodules.

PATIENTS AND METHODS

From October 2014 to July 2015, liver specimens from 30 consecutive patients were analyzed ex vivo using pCLE directly after resection, with indocyanine green as contrast agent. The final diagnosis was obtained histologically, as per standard of care. In phase 1, a pathologist and a physicist established pCLE image criteria to distinguish normal parenchyma, malignant nodules, and metastases that had completely responded to chemotherapy. In phase 2, a pathologist and a surgeon reviewed selected videos retrospectively to assess the effectiveness of these.

RESULTS

In phase 1, the healthy nodules were characterized by fluorescent hepatocytes with nonfluorescent nuclei and the malignant nodules were identified as strongly fluorescent, irregular cancer-cell clusters. The extracellular matrix was substantially less fluorescent compared with the cancerous clusters of cells. After chemotherapy, a very dense and strongly fluorescent fibrosis replaced tubular structures of cancerous cells. The retrospective evaluation in phase 2 resulted in 78 and 100% sensitivity, 100 and 89% specificity, 90 and 100% positive predictive value, and 90 and 100% negative predictive value for the surgeon and the pathologist, respectively, for the detection of malignant nodules.

CONCLUSION

This series emphasized that characterization of liver metastases is possible with pCLE, with high performance results.

An overview of imaging techniques for liver metastases management

Evaluation of liver metastases is one of the most common indications for liver imaging. Imaging plays a key role in the of assessment liver metastases. A variety of imaging techniques, including ultrasonography, computed tomography, MRI and PET combined with CT scan are available for diagnosis, planning treatment, and follow-up treatment response. In this paper, the authors present the role of imaging for the assessment of liver metastases and the contribution of each of the different imaging techniques for their evaluation and management. Following recent developments in the field of oncology, the authors also present the importance of imaging for the assessment of liver metastases response to therapy. Finally, future perspectives on imaging of liver metastases are presented.

Intraoperative Contrast-Enhanced Ultrasound in Colorectal Liver Metastasis Surgery Improves the Identification and Characterization of Nodules

INTRODUCTION

The sensitivity of preoperative assessment of colorectal liver metastases (CRLM) ranges from 74 to 80%. Intraoperative ultrasound (IOUS) associated with contrast-enhanced intraoperative ultrasound (CE-IOUS) may be able to improve this. Thus, the aims of this study were to assess the value of IOUS and CE-IOUS for the surgical approach and to determine risk factors both for the detection of new nodules and for the modification of the surgical strategy.

MATERIALS AND METHODS

Forty-three patients who underwent CRLM surgery were included. These patients had an MRI in the 8 weeks preceding surgery and benefited from intraoperative IOUS and CE-IOUS.

RESULTS AND DISCUSSION

The use of IOUS/CE-IOUS permitted the identification of 43 additional lesions and an improved characterization of nodules in 23 patients with a resulting modification of surgical strategy. Lesions were down-staged in six patients and up-staged in six patients. Chemotherapy (p = 0.02) and the presence of nodules in the left lobe (p = 0.04) were predictive factors for finding new nodules at IOUS/CE-IOUS. The discovery of a new nodule systematically modified surgical management. IOUS/CE-IOUS improved intraoperative management of liver metastases. The techniques enable pertinent modification of surgical resections and a reduction of residual lesions.

Video assisted resections. Increasing access to minimally invasive liver surgery?

Objective: To evaluate perioperative outcomes, safety and feasibility of video-assisted resection for primary and secondary liver lesions. Methods : From a prospective database, we analyzed the perioperative results (up to 90 days) of 25 consecutive patients undergoing video-assisted resections in the period between June 2007 and June 2013. Results : The mean age was 53.4 years (23-73) and 16 (64%) patients were female. Of the total, 84% were suffering from malignant diseases. We performed 33 resections (1 to 4 nodules per patient). The procedures performed were non-anatomical resections (n = 26), segmentectomy (n = 1), 2/3 bisegmentectomy (n = 1), 6/7 bisegmentectomy (n = 1), left hepatectomy (n = 2) and right hepatectomy (n = 2). The procedures contemplated postero-superior segments in 66.7%, requiring multiple or larger resections. The average operating time was 226 minutes (80-420), and anesthesia time, 360 minutes (200-630). The average size of resected nodes was 3.2 cm (0.8 to 10) and the surgical margins were free in all the analyzed specimens. Eight percent of patients needed blood transfusion and no case was converted to open surgery. The length of stay was 6.5 days (3-16). Postoperative complications occurred in 20% of patients, with no perioperative mortality. Conclusion : The video-assisted liver resection is feasible and safe and should be part of the liver surgeon armamentarium for resection of primary and secondary liver lesions.

Role of laparoscopic ultrasound during diagnostic laparoscopy for proximal biliary cancers: a single series of 100 patients

BACKGROUND

Despite extensive preoperative evaluation, a significant proportion of patients with biliary cancer (BC) proves to be unresectable at laparotomy. Diagnostic laparoscopy (DL) has been suggested to avoid unnecessary laparotomy. Aim of the study was to evaluate the additional benefit of combining LUS to DL in patients with proximal BC.

METHODS

Inclusion criteria were all patients affected by proximal BC undergone DL + LUS based on the following criteria: preoperative diagnosis of gallbladder cancer, hilar cholangiocarcinomas (HC) and borderline resectable intrahepatic cholangiocarcinoma (IHC). The overall yield (OY) and accuracy (AC) of DL ± LUS in determining unresectable disease were calculated.

RESULTS

From 01/2006 to 12/2014, 107 out of 191 (56%) potentially resectable proximal BC were evaluated. One hundred patients fulfilled inclusion criteria: 44 IHC, 21 GC and 35 HC. Forty-eight (48%) patients were male with median age of 65 (41-87) years. The median number of preoperative imaging was 3 ± 0.99. Patients underwent DL + LUS 10.5 ± 15.6 days after last imaging. DL + LUS identified unresectable diseases in 24 patients, 6 (25%) of them only thanks to LUS findings (3 GC and 3 IHC). At laparotomy, 6 (4 HC and 2 GC) out of 76 patients were found unresectable because of carcinomatosis (n = 2), new liver metastasis (n = 2) and vascular invasion (n = 2). LUS increased the OY (from 18 to 24%) and AC (from 60 to 80%) in the whole group. The advantages of LUS were confirmed for GC (OY from 38.1 to 52.4%, AC from 61.5 to 84.6%) and IHC patients (OY from 11.4 to 18.2%, AC from 62.5 to 100%) but not for HC group. The presence of biliary drainage was the only factor able to predict negative yield (p < 0.001).

CONCLUSIONS

LUS increases overall yield and accuracy of DL for detecting unresectable disease in patients with preoperative diagnosis of gallbladder cancer and borderline resectable intrahepatic cholangiocarcinomas.

Usefulness of intraoperative ultrasonography in liver resections due to colon cancer metastasis

INTRODUCTION

Intraoperative ultrasonography (IOUS) of the liver has been used both as an aid for intraoperative anatomical definition and for the detection of new lesions. The present study aimed to evaluate the impact of IOUS and to identify factors that can predict the detection of new lesions intraoperatively.

METHODS

In this observational and prospective study, with a cross-sectional design, patients with colorectal cancer metastases who underwent hepatectomy were selected. Abdominal computed tomography, magnetic resonance imaging, and positron emission tomography were the preoperative evaluation tests. All patients underwent IOUS performed by the same surgeon. The intraoperative findings were compared with the preoperative tests results.

RESULTS

In total, 56 hepatectomies were evaluated. Half of the patients were men, with a mean age of 57 (30-85) years. New lesions were found intraoperatively in 12 patients (21.4% of cases) and were detected on both palpation and ultrasonography in 11 of these patients. Ultrasonography helped to revise the surgical plans by providing additional information in 35.7% of cases. On multivariate analysis, the presence of more than 4 preoperative nodules was predictive of the intraoperative occurrence of new lesions.

CONCLUSIONS

IOUS remains the only way to evaluate the relationships between tumors, liver vascular structures, and bile ducts intraoperatively. Alone, IOUS was not useful for identifying new lesions intraoperatively, as all new lesions were also detected on palpation. The number of lesions diagnosed on preoperative tests influenced the probability of identifying new lesions intraoperatively. There may be additional influential factors.

Is intraoperative ultrasound still useful for the detection of colorectal cancer liver metastases?

BACKGROUND

Debate on the optimal mode of preoperative imaging in the management of colorectal liver metastases (CRLM) is ongoing and, despite its longstanding use, the precise role of intraoperative ultrasonography (IOUS) is not well established. This study evaluates the impact of IOUS in the era of high-quality, cross-sectional imaging techniques.

METHODS

All patients who underwent liver resection for CRLM in a tertiary care referral centre from January 2006 to December 2013 were included. All patients were submitted to computed tomography (CT) and/or liver magnetic resonance imaging (MRI) before surgery. Intraoperative US was performed mainly to detect previously non-diagnosed tumours that would change the surgical strategy.

RESULTS

A total of 225 liver resections were performed. Liver MRI and CT scans were available for 202 patients (89.8%) and 225 patients (100%), respectively. Radiological reports recorded 632 liver tumours in 219 patients (i.e. 2.9 lesions per patient). The median time between preoperative liver MRI and surgical resection was 36 days. Intraoperative inspection, palpation and US found 20 additional lesions in 18 patients (8.0%), in three of whom lesions were diagnosed only on IOUS (1.4%). Overall, only 12 of the 20 lesions were malignant.

CONCLUSIONS

Although CT and liver MRI are commonly used, IOUS alone allows the discovery of a few additional lesions that result in a change of surgical strategy in 1.4% of cases.

The role of intraoperative ultrasonography in the diagnosis and management of focal hepatic lesions

Intraoperative ultrasonography (IOUS) has been widely utilized in hepatic surgery both as a diagnostic technique and in the course of treatment. Since IOUS involves direct-contact imaging of the target organ, it can provide high spatial resolution without interference from the surrounding structures. Therefore, IOUS may improve the detection, characterization, localization, and local staging of hepatic tumors. IOUS is also a real-time imaging modality capable of providing interactive information and valuable guidance in a range of procedures. Recently, contrast-enhanced IOUS, IOUS elastography, and IOUS-guided hepatic surgery have attracted increasing interest and are expected to lead to the broader implementation of IOUS. Herein, we review the various applications of IOUS in the diagnosis and management of focal hepatic lesions.