Colorectal cancer is the fourth most frequently diagnosed cancer and the second leading cause of cancer death in the United States. In 2016, approximately 39,000 new cases of rectal cancer will be diagnosed and 49,000 patients will die from colorectal cancer combined [1]. Between 50 and 60% of patients diagnosed with colorectal cancer will develop metastatic disease [2] with 80–90% of patients having unresectable hepatic metastatic burden [3]. Most patients will present with metachronous liver metastatic disease. However, like our patient, 15–34% of patients with colorectal cancer present with synchronous liver metastatic disease [4–8].

Untreated patients have a median survival of 12 months or less [9]. Patients who undergo surgical resection in the context of multimodality therapy are the only patients with a chance at long-term cure, and 5-year survival is achieved in approximately 50% of patients [10].

The management of patients who present with colorectal cancer with synchronous metastatic disease is complex. Decisions regarding timing of surgery, chemotherapy or chemoradiotherapy, and surgical approach are influenced by tumor biology, primary tumor location, extent of hepatic metastatic disease, and patient comorbidities. All patients should undergo a comprehensive history and physical examination. Prior abdominal surgery or the presence of underlying comorbidities, such as chronic obstructive pulmonary disease or congestive heart failure, should be kept in mind when choosing patients for minimally invasive hepatectomy.

Standard workup of patients with hepatic malignancy includes a triphasic CT scan (noncontrast, arterial, and portal venous phase) or contrast-enhanced MRI exam of the abdomen and pelvis. These imaging studies should be recent (within 4–6 weeks of surgery), and allow for evaluation of tumor size and location, extent of hepatic disease, assessment of the background liver for cirrhosis and hepatic steatosis, and the size of the future liver remnant. Evaluation for extrahepatic disease can be accomplished with a CT scan of the chest or CT/PET imaging. Routine labs include complete blood count, coagulation panel, and hepatic function panel. The serum CEA is useful as part of the diagnostic workup and postoperative surveillance.

Similar to open hepatectomy, we favor a low central venous pressure (CVP) anesthesia approach when performing minimally invasive hepatic resections [11]. This avoids distention of the inferior vena cava, facilitating mobilization of the liver and dissection of the retrohepatic cava and major hepatic veins. Low CVP anesthesia decreases bleeding during parenchymal transection and simplifies control of inadvertent venous injury. The incidence of gas embolism is rare during laparoscopic liver resection [12].

All patients with metastatic colorectal cancer should be discussed by a multidisciplinary panel of physicians, including colorectal and hepato-pancreato-biliary (HPB) surgeons, medical oncologists, radiation oncologists, interventional radiologists, gastroenterologists, pathologists, and palliative care providers. For our patient, the consensus of the multidisciplinary tumor board was to initiate systemic chemotherapy with 5-fluorouracil, leucovorin, oxaliplatin, and bevacizumab, with restaging after four cycles (2 months). There is no survival benefit to more than 2–3 months (four to six cycles) of preoperative chemotherapy, but liver-related posthepatectomy complications increase [13].

There is no consensus regarding the optimal management of patients with synchronous colorectal cancer and liver metastases. One option is the staged approach, addressing the primary first, followed by chemotherapy and hepatectomy at a later date. Theoretically, this approach eliminates potential complications from the primary tumor, such as bleeding, perforation, or obstruction. However, these complications arise in fewer than 10% of patients presenting with Stage IV colorectal cancer who receive systemic treatment in the setting of an intact primary [14]. Addressing the primary first delays the treatment of liver metastastic disease, which is of the greatest risk to long-term survival. Conversely, the liver metastatic disease can be addressed first, followed by colectomy and adjuvant chemotherapy. Alternatively, the patient can receive preoperative chemotherapy, followed by simultaneous or staged resection. A recent meta-analysis found that no single approach was superior to the others in terms of postoperative morbidity, mortality, or 5-year overall survival [6]. Given the lack of prospective data to guide decision-making, the order of therapy should be dictated by the extent of surgery that would be required to clear both the primary and the liver metastases [15]. For patients with less disease burden, consideration should be given to up-front simultaneous resection of both the primary and the liver metastatic diseases (i.e., solitary liver metastasis with a right colon cancer). Patients who would require extensive surgery to clear either the primary (i.e., proctosigmoidectomy or abdominoperineal resection) and/or the liver metastases (i.e., formal lobectomy or extended hepactectomy) warrant preoperative chemotherapy in an attempt to downstage disease and the extent of surgery required. Depending on the response, simultaneous or staged approaches can then be undertaken.

Minimally invasive hepatectomy is being performed with increasing frequency. In the largest review of laparoscopic liver resections to date, Nguyen et al. analyzed case series totaling more than 2,800 cases [23]. The overall findings suggest that minimally invasive liver resection is both safe and feasible. Nearly 75% of the cases were performed purely laparoscopic. Nearly 50% of resections were for malignancy, and the majority of cases (65%) were minor resections, including wedge hepatectomy or left lateral sectionectomy. Formal lobectomy was performed in 15% of cases, and fewer than 1% of the cases were extended lobectomies. Perioperative death occurred in 0.3% of the patients. The overall complication rate was 11%, with the most common complications being bile leak (1.5%) and transient hepatic dysfunction (1%).

Several series have compared laparoscopic to open major liver resection [50–53]. Laparoscopic resections appear to be associated with less blood loss, fewer postoperative complications, and shorter hospital length of stay, with the trade-off being slightly longer operative times. Short- and long-term oncologic outcomes of laparoscopic liver resections are comparable to disease-matched open outcomes [54, 55].

There are eight series in the literature that compare robotic-assisted liver resection to laparoscopic liver resection [34, 49, 56–61]. Data are summarized in Table 8.1. The largest experience belongs to the group of Tsung et al. at the University of Pittsburgh [34]. Each of the 57 patients who underwent robotic hepatectomy were retrospectively matched in a 1:2 ratio to patients that underwent laparoscopic liver resection, with emphasis on background liver disease, extent of resection, diagnosis, American Society of Anesthesiologists (ASA) score, age, body mass index (BMI), and gender. There was no difference in blood loss, transfusion requirements, conversion rate, complication rate, or length of stay. Robotic-assisted procedures took significantly longer (253 vs. 199 min). There appeared to be a learning curve effect when comparing the initial 13 robotic procedures to the subsequent 44, as there were significant reductions in blood loss (300 vs. 100 ml), operative times (381 vs. 232 min), and length of stay (5 vs. 4 days). However, the comparison of robotic-assisted to surgery to conventional laparoscopy may not be worthwhile, because the robotic platform should be looked at as an advanced tool to overcome the inherent limitations of conventional laparoscopy, thus expanding the repertoire of complex minimally invasive procedures that can be applied to the liver, pancreas, and biliary tract.