Revisiting liver anatomy and terminology of hepatectomies. Ann Surg. 2013;257:383-386. [PMID: 23386236 DOI: 10.1097/sla.0b013e31827f171f]

[Vascular management in anatomical liver resection]

The vascular management in anatomical liver resection plays a pivotal role in maintaining an adequately functional residual liver volume. In this respect it is essential to guarantee an adequate portal and arterial inflow as well venous outflow for the whole residual liver (lobe or segments). To achieve this, the liver surgeon should have excellent perioperative imaging, surgical expertise based on knowledge of vascular anatomy, physiology and hemodynamics of the liver and a well-designed and cautious operative strategy. The use of intraoperative ultrasonography (with or without contrast enhancement) and modern parenchymal dissectors (e.g. ultrasound or water jet dissectors) are strongly recommended.

Multiple Tumors Located in the Same Section Are Associated with Better Outcomes After Hepatic Resection for HCC Patients Meeting the Milan Criteria

The impact of the tumor location on the outcome after hepatic resection (HR) in multifocal hepatocellular carcinoma (HCC) is still poorly understood. The aim of this study was to compare the short- and long-term outcomes of HR patients with multifocal tumors meeting the Milan criteria and tumors located in the same or different sections. A total of 219 consecutive HR patients with multifocal tumors meeting the Milan criteria were divided into group SS (n = 97; same section) and group DS (n = 122; different sections) according to their anatomical location (Couinaud's segmentation). The prognostic predictors were evaluated, and a subgroup analysis was performed. The 1-, 3-, and 5-year overall survival (OS) and recurrence-free survival (RFS) rates were significantly higher in group SS than group DS. The subgroup analysis showed that patients with two tumors in the same section and patients undergoing en bloc resection had better OS and RFS. A multivariate analysis revealed that tumors located in different sections and macrovascular invasion were independent predictors of poor prognosis. In HCC patients with multifocal tumors meeting the Milan criteria, tumors located in the same hepatic section may lead to better long-term survival and lower HCC recurrence rates than tumors in different sections after HR.

The Preference for Anterior Approach Major Hepatectomy: Experience Over 3 Decades and a Propensity Score-Matching Analysis in Right Hepatectomy for Hepatocellular Carcinoma

Surgical treatment for primary hepatocellular carcinoma (HCC) has progressed enormously over time. The aim of this study was to analyze the evolution of surgical techniques and outcomes of patients undergoing major right hepatectomy (RH) over the last few decades.A retrospective review of 557 consecutive patients who had undergone RH for HCC between January 1982 and December 2011 was performed. Patients were categorized into subgroups and analyzed according to period and surgical approach to hepatectomy. Based on a propensity score-matching model, the surgical approach in patients in the second period was also analyzed in terms of anterior approach (AA) and conventional approach (CA)-RH.Tumor factors remained the most important prognostic factors related to postoperative HCC recurrence throughout the 2 periods examined in this study. Comparison of patients selected by a propensity score-matching model showed that AA-RH led to significantly better outcomes including recurrence-free survival (RFS) (P = 0.011) and overall survival (OS) (P = 0.012) in patients with HCC as compared with CA-RH. The 5-year RFS and OS were 33.4% and 52.2% after AA-RH, and 21.0% and 36.5% after CA-RH.Major hepatectomy has evolved into a safe procedure that can be performed with confidence. RH by an AA has shown several advantages over CA-RH, and can thus be recommended as the standard procedure for liver resection in patients who require right hepatectomy.

Developmental anatomy of the liver from computerized three-dimensional reconstructions of four human embryos (from Carnegie stage 14 to 23)

BACKGROUND & AIM

Some aspects of human embryogenesis and organogenesis remain unclear, especially concerning the development of the liver and its vasculature. The purpose of this study was to investigate, from a descriptive standpoint, the evolutionary morphogenesis of the human liver and its vasculature by computerized three-dimensional reconstructions of human embryos.

MATERIAL & METHODS

Serial histological sections of four human embryos at successive stages of development belonging to three prestigious French historical collections were digitized and reconstructed in 3D using software commonly used in medical radiology. Manual segmentation of the hepatic anatomical regions of interest was performed section by section.

RESULTS

In this study, human liver organogenesis was examined at Carnegie stages 14, 18, 21 and 23. Using a descriptive and an analytical method, we showed that these stages correspond to the implementation of the large hepatic vascular patterns (the portal system, the hepatic artery and the hepatic venous system) and the biliary system.

CONCLUSION

To our knowledge, our work is the first descriptive morphological study using 3D computerized reconstructions from serial histological sections of the embryonic development of the human liver between Carnegie stages 14 and 23.

Defining perioperative risk after hepatectomy based on diagnosis and extent of resection

Outcomes after hepatectomy have been assessed incompletely and have not been stratified by both extent of resection and diagnosis. We hypothesized that operative risk is better assessed by stratifying diagnoses into low- and high-risk categories and extent of resection into major and minor resection categories to more accurately evaluate the outcomes after hepatectomy. ACS-NSQIP was reviewed for 30-day operative mortality and major morbidity after partial hepatectomy (PH), left hepatectomy (LH), right hepatectomy (RH), and trisectionectomy (TS). Mortality was reviewed per diagnosis. "High Risk" was defined as the diagnoses associated with the greatest mortality. Major and minor resections were defined by comparison of outcomes for extent of resection by univariate analysis. Chi-square tests, t tests, Fisher's exact tests, and multivariable logistic regression were utilized to compare the outcomes across groups. Among the 7,043 patients, the greatest mortality was observed with hepatocellular carcinoma (5.2%) and cholangiocarcinoma (8.2%), either intra- or extrahepatic, which were classified "High Risk". Metastatic disease, benign neoplasms, and gallbladder cancer had a mortality rate of 1.3, 0.5, and 1.0%, respectively, and were classified "Low Risk". PH and LH were similar statistically for operative mortality and major morbidity within respective diagnosis risk groups (Low Risk: PH vs. LH and High Risk: PH vs. LH; all p > 0.05) and were defined as "Minor Resections". Similarly, RH and TS had similar operative mortality and major morbidity within respective diagnosis risk groups (Low Risk: RH vs. TS and High Risk: RH vs. TS; all p > 0.05) and were defined as "Major Resections". Risks of major morbidity and mortality increased for both diagnoses and the extent of resection. With minor resections, mortality and major morbidity were 5 and 1.6 times greater respectively for high-risk diagnosis than for low-risk diagnosis. With major resections, mortality and major morbidity were 4 and 1.6 times greater, respectively, for high-risk diagnoses than low-risk diagnoses. With low-risk diagnoses, mortality and major morbidity were 2.9 and 1.7 times greater, respectively, for major resections than minor resections (p < 0.001). With high-risk diagnoses, mortality and major morbidity were 2.3 and 1.7 times greater, respectively, for major resections than minor resections (all p < 0.001). Regardless of the extent of resection, high-risk diagnoses were independently associated with mortality (OR = 3.2 and 3.1, respectively) and major morbidity (OR = 1.5 and 1.5, respectively). Risk of hepatectomy is better assessed when stratified by both the diagnostic risk and the extent of resection. Accurate assessment of these outcomes has significant implications for preoperative planning, informed consent, resource utilization, and inter-institutional comparisons.

Mesohepatectomy for centrally located large hepatocellular carcinoma: Indications, techniques, and outcomes

BACKGROUND

Whether mesohepatectomy should be performed for large hepatocellular carcinoma (HCC) located in the central part of the liver is controversial, and the safety and long-term survival after this operation remain to be investigated.

METHODS

Between January 2002 and December 2012, 696 patients with HCC located in the central part of the liver who received liver resection in our hospital were included in this study. These patients were divided into three groups: 158 patients with large HCC (tumor size >5.0 cm) and 192 patients with small HCC (tumor size ≤ 5.0 cm) who received mesohepatectomy were classified as the mesohepatectomy for large HCC (MHG-L) group and the mesohepatectomy for small HCC (MHG-S) groups, respectively, and 346 patients with large HCC who received hemihepatectomy or less were classified as the non-mesohepatectomy for large HCC (NMHG-L) group. The operative indications, techniques, and outcomes of the three groups were analyzed retrospectively.

RESULTS

There were no substantial differences among the three groups in in-hospital mortality or postoperative complication rates. The overall survival and disease-free survival were not different between the MHG-L group and the NMHG-L group or between the MHG-L group and the MHG-S group. Univariable and multivariable analyses of the MHG-L mesohepatectomy group indicated that cirrhosis, tumor number, and vascular invasion were independent risk factors of poor long-term survival of mesohepatectomy. In the MHG-L and NMHG-L groups, solitary large hepatocellular carcinoma had better long-term survival than nodular large hepatocellular carcinoma.

CONCLUSION

Mesohepatectomy is safe and efficacious for BCLC B/C patients who have centrally located large HCC, especially for solitary tumors, with good survival outcomes.

Anatomy of the liver: an outline with three levels of complexity--a further step towards tailored territorial liver resections

The vascular anatomy of the liver can be described at three different levels of complexity according to the use that the description has to serve. The first--conventional--level corresponds to the traditional 8-segments scheme of Couinaud and serves as a common language between clinicians from different specialties to describe the location of focal hepatic lesions. The second--surgical--level, to be applied to anatomical liver resections and transplantations, takes into account the real branching of the major portal pedicles and of the hepatic veins. Radiological and surgical techniques exist nowadays to make full use of this anatomy, but this requires accepting that the Couinaud scheme is a simplification, and looking at the vascular architecture with an unprejudiced eye. The third--academic--level of complexity concerns the anatomist, and the need to offer a systematization that resolves the apparent contradictions between anatomical literature, radiological imaging, and surgical practice. Based on the real number of second-order portal branches that, although variable averages 20, we submit a system called the "1-2-20 concept", and suggest that it fits best the number of actual--as opposed to idealized--anatomical liver segments.

Clinical and surgical anatomy of the liver: a review for clinicians

The liver is the largest gland in the body occupying 2.5% of total body weight and providing a host of functions necessary for maintaining normal physiological homeostasis. Despite the complexity of its functions, the liver has a homogenous appearance, making hepatic anatomy a challenging topic of discussion. To address this issue, scholars have devoted time to establishing a framework for describing hepatic anatomy to aid clinicians. Work by the anatomist Sir James Cantlie provided the first accurate division between the right and left liver in 1897. The French surgeon and anatomist Claude Couinaud provided additional insight by introducing the Couinaud segments on the basis of hepatic vasculature. These fundamental studies provided a framework for medical and surgical discussions of hepatic anatomy and were essential for the advancement of modern medicine. In this article, the authors review the normal anatomy and physiology of the liver with a view to enhancing the clinician's knowledge base. They also provide a convenient model to assist with understanding and discussion of liver anatomy.

Vascular reconstruction combined with liver resection for malignant tumours

BACKGROUND

The resectability criteria for malignant liver tumours have expanded during the past two decades. The use of vascular reconstruction after hepatectomy has been integral in this process. However, the majority of reports are anecdotal. This is a retrospective analysis of the techniques, morbidity, mortality and risk factors of liver resections with vascular reconstruction based on a large series from a single centre.

METHODS

Patients who underwent hepatic resection combined with vascular resection and reconstruction between 1997 and 2009 were included in this study. Indications for surgery, morbidity and 90-day mortality are reported along with factors predictive of operative mortality.

RESULTS

Eighty-four patients had liver resection with 97 vascular resections and reconstruction. There were 44 men and 40 women with a mean(s.d.) age of 56·9(12·1) years. Mean(s.d.) follow-up was 37·3(34·1) months. All patients had primary or metastatic liver tumours. The perioperative morbidity rate was 62 per cent (52 patients) and the operative mortality rate 14 per cent (12). Predictors of operative mortality were: bilirubin level exceeding 34 µmol/ml (P = 0·023), indocyanine green retention rate at 15 min over 10 per cent (P = 0·031), duration of ischaemia (P = 0·011), amount of blood transfused (P = 0·025) and combined major extrahepatic procedure (P = 0·042). Actuarial 3- and 5-year survival rates were 44 and 26 per cent respectively.

CONCLUSION

Liver resection with combined vascular resection and reconstruction can be performed in selected patients with acceptable morbidity and mortality. The lack of therapeutic alternatives and the poor outcome of non-operative management seem to justify this approach. The identification of risk factors should help improve patient selection and postoperative outcome as well as facilitate objective risk communication with surgical candidates.

Concepts for Liver Segment Classification: Neither Old Ones nor New Ones, but a Comprehensive One

Concepts dealing with the subdivision of the human liver into independent vascular and biliary territories are applied routinely in radiological, surgical, and gastroenterological practice. Despite Couinaud's widely used eight-segments scheme, opinions on the issue differ considerably between authors. The aim of this article is to illustrate the scientific basis for understanding and harmonizing inconsistencies between seemingly contradictory observations. Possible clinical implications are addressed.

Management of abdominal malignancies: updates from the International Association of Surgeons, Gastroenterologists and Oncologists

The 22nd World Congress of the International Association of Surgeons, Gastroenterologists and Oncologists was held from 5-8 December 2012 in Bangkok, Thailand. Themed 'Challenges and Controversies in the Management of Abdominal Diseases: Current Possibility and Future Expectation', the congress featured ten main topics including: upper GI tract surgery, lower GI tract surgery, hepatic surgery, biliary tract surgery, pancreatic surgery, interventional chemo-immuno-radiotherapy, laparoscopic endoscopic surgery, multidisciplinary approaches, innovation and advanced technology and robotic surgery. Approximately 200 guest speakers were invited to share their experiences and expertise, while 600 abstracts were submitted for oral and poster presentations. In this article, the authors highlight and summarize some of the presentations from this conference.