A new look on liver anatomy: needs and means to go beyond the Couinaud scheme

Laparoscopic anatomical portal territory hepatectomy using Glissonean pedicle approach (Takasaki approach) with indocyanine green fluorescence negative staining: how I do it

BACKGROUND

Laparoscopic anatomical resection (LAR) is a highly challenging procedure. This study aimed to describe our experience of the LAR with an indocyanine green fluorescence negative staining (ICGNS) by the Glissonean pedicle transection (Takasaki) approach.

METHODS

From April 2017 to December 2019, 43 consecutive patients underwent LAR with ICGNS strategy in our medical team. The details of the ICGNS strategy were described. The demographic and clinicopathological data of the included patients were retrospectively analyzed.

RESULTS

The extent of resections included right hemihepatectomy (n = 12), left hemihepatectom (n = 4), left lateral sectionectomy (n = 3), Right anterior sectionectomy (n = 3), Right posterior sectionectomy (n = 6), central hepatectomy (n = 2), single anterolateral segmentectomy (n = 5), single posterosuperior segmentectomy (n = 6), and bisegmentectomy (n = 2). The mean operation time was 212 ± 53 min, and the median estimated blood loss was 200 (100-300) ml. The overall complication rate was 30.2% (grade I, 14%; grade II, 14%; grade III, 2.3%). The median duration of postoperative hospital stay was 6 (4-7) days.

CONCLUSION

ICGNS is a safe and feasible LAR strategy that greatly facilitates selecting the liver transection plane, although its benefits need to be verified by large-sample comparative studies.

The Effect of Three-Dimensional Preoperative Simulation on Liver Surgery

Background

In the past decade, three-dimensional (3D) simulation has been commonly used for liver surgery. However, few studies have analyzed the usefulness of this 3D simulation. The aim of this study was to evaluate the effect of 3D simulation on the outcome of liver surgery.

Methods

We retrospectively analyzed 240 consecutive patients who underwent liver resection. The patients were divided into two groups: those who received 3D preoperative simulation (“3D group”, n = 120) and those who did not undergo 3D preoperative simulation (“without 3D group”, n = 120). The perioperative outcomes, including operation time, blood loss, maximum aspartate transaminase level, length of postoperative stay, postoperative complications and postoperative mortality, were compared between the two groups. The predicted resected liver volume was compared with the actual resected volume.

Results

The median operation time for the 3D group was 36 min shorter than that for the without 3D group (P = 0.048). There were no significant differences in other outcomes between the two groups. A subgroup analysis revealed that the operation time of repeated hepatectomy and segmentectomy for the 3D group was shorter than that for the without 3D group (P = 0.03). There was a strong correlation between the predicted liver volume and the actual resected liver weight (r = 0.80, P < 0.001).

Conclusion

These findings demonstrate that 3D preoperative simulation may reduce the operation time, particularly for repeated hepatectomy and segmentectomy.

Human liver segments: role of cryptic liver lobes and vascular physiology in the development of liver veins and left-right asymmetry

Couinaud based his well-known subdivision of the liver into (surgical) segments on the branching order of portal veins and the location of hepatic veins. However, both segment boundaries and number remain controversial due to an incomplete understanding of the role of liver lobes and vascular physiology on hepatic venous development. Human embryonic livers (5-10 weeks of development) were visualized with Amira 3D-reconstruction and Cinema 4D-remodeling software. Starting at 5 weeks, the portal and umbilical veins sprouted portal-vein branches that, at 6.5 weeks, had been pruned to 3 main branches in the right hemi-liver, whereas all (>10) persisted in the left hemi-liver. The asymmetric branching pattern of the umbilical vein resembled that of a "distributing" vessel, whereas the more symmetric branching of the portal trunk resembled a "delivering" vessel. At 6 weeks, 3-4 main hepatic-vein outlets drained into the inferior caval vein, of which that draining the caudate lobe formed the intrahepatic portion of the caval vein. More peripherally, 5-6 major tributaries drained both dorsolateral regions and the left and right ventromedial regions, implying a "crypto-lobar" distribution. Lobar boundaries, even in non-lobated human livers, and functional vascular requirements account for the predictable topography and branching pattern of the liver veins, respectively.

Reviewing the diagnostic criteria for acute-on-chronic liver failure

For over 20 years, acute-on-chronic liver failure (ACLF) has taken multiple definitions and/or classifications. The definition outlines the acute and chronic insults to include a homogenous patient group with liver failure and an expected outcome in a specific time frame. Early and accurate diagnosis is essential as this inflammation of the liver may tilt the balance of liver destruction and regeneration adversely. Various factors such as superadded systemic sepsis, liver reserve, cause of primary chronic liver disease, state of immune system or the state of gut microbial flora might determine the ultimate prognosis. Areas covered: To date, there has been no universally accepted definition of ACLF. In this review, we discuss the strengths and weaknesses, controversies and basis for early identification and accurate diagnosis of ACLF. PubMed and Google scholar database searches were conducted, search terms included 'acute on chronic liver failure,' 'ACLF,' and 'diagnostic criteria.' Expert commentary: With recent advances in the management of advanced cirrhosis, research will gradually shift towards ACLF in the near future, focusing on the pathogenesis, new treatment options and improving survival. Once we improve understanding of this syndrome, newer definitions will evolve, thereby enabling earlier diagnosis and novel therapeutic avenues.

Total abdominal approach for postero-superior segments (7, 8) in laparoscopic liver surgery: a multicentric experience

Laparoscopic liver resections are frequently performed for peripheral lesions located in the antero-inferior segments. Resection of postero-superior segments is more demanding and dangerous than other segmentectomies, resulting in a longer operation time and increased blood loss. To reduce technical challenges, some authors advocated a modified surgical approach for these segments with the patient placed in the left lateral decubitus with the right arm suspended and suggested technical variations like the use of an additional intercostal trocar, the placement of one or two additional trans-thoracic trocars, a hand-assisted approach or a hybrid method with a median laparotomy. In the present series of 88 patients from four hepatobiliary centers with high volume of activity in Italy, a standard lithotomic position has been routinely used without the need for left lateral decubitus or semi-prone position and through abdominal wall without use of trans-thoracic trocars. This approach allows a more comfortable use of the Pringle maneuver that we used routinely in hepatic resection for PS segments; and, a very short time is needed for conversion, whenever it is required. In our series, laparoscopic resection of liver tumors located in the postero-superior segments of the liver with a total abdominal approach is technically feasible and safe with short-term results similar to other laparoscopic liver resections.

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.