Study on the portal ramification pattern of the right anterior sector of the liver and a unique medial branch (PV8c) of the right anterior portal vein.

Aim: The concept of Couinaud segmentation is widely used in clinical practice. However, there were no definite anatomical landmarks between segments V and VIII. Therefore, segmentation of the right anterior sector is still controversial. We aimed to investigate the portal segmentation of the right anterior sector using 3D image analysis, and to reveal the existence of the medial branch (PV8c), a unique, characteristic branch of the right anterior portal vein. Methods: The ramification form and pattern of the tertiary portal branch of the right anterior portal vein were retrospectively analyzed, and the frequency of PV8c was evaluated in 261 patients between January 2016 and June 2020. Results: The ramification pattern of tertiary portal branches of the right anterior portal vein was classified into four types: craniocaudal, 28.0% of patients; ventrodorsal, 21.8%; trifurcation, 39.5%; and quadfurcation, 5.7%, and each type was further subdivided into six patterns by focusing especially on the caudal branches. The ramification pattern in the remaining 5.0% of the livers did not belong to the above-mentioned four types. The PV8c branch was identified in 140 of 261 livers (53.6%); the mean proportion of the feeding area of PV8c in the whole liver volume was 3.4%. Conclusion: Since the ramification pattern of tertiary portal branches of the right anterior portal vein does not necessarily show a single pattern, it is important to confirm the portal vein branching in each case during hepatectomy. This is the first study of the details of PV8c by 3D computed tomography.

Parenchymal-sparing approaches for resection of tumors located in the paracaval portion of the caudate lobe of the liver-utility of limited resection and central hepatectomy.

PURPOSE: Resection of liver cancer involving the paracaval portion (PC) of the caudate lobe is challenging because the PC is located deepest in the liver. This study aimed to elucidate the utility of two parenchymal-sparing approaches of limited resection and central hepatectomy for resecting tumors located in the PC. METHODS: In 2018 and 2020, 12 out of 143 patients underwent hepatectomy for tumors located in the PC of the liver. In six patients, limited resection (LR) of the PC after full mobilization of the liver off the inferior vena cava (IVC) was performed for tumors excluding the hilar plate or large hepatic veins (large HVs), including major hepatic veins or thick short hepatic veins. In six patients, central hepatectomy (CH) using liver tunnel was performed for tumors involving or close to the hilar plate and/or large HVs. RESULTS: During CH, the surgical view of the cranial side of the hilar plate was wide enough to perform combined resection of the large HVs in front of the IVC. Five of the six CHs were performed with resection of the LHVs. No LRs were accompanied with resection of the LHVs. The CH was associated with longer Pringle's time (76 min vs. 29.5 min, p = 0.015) and blood loss (1104 ml vs. 370 ml, p = 0.041). The preserved liver parenchyma volumes were 82% and 95% of the total liver volume after CH and LR, respectively. CONCLUSION: Our parenchymal-sparing approach for resection of liver cancer located in the PC is feasible for curative resection.

Algorithm for Resecting Hepatocellular Carcinoma in the Caudate Lobe.

OBJECTIVE: To propose an algorithm for resecting hepatocellular carcinoma (HCC) in the caudate lobe. BACKGROUND: Owing to a deep location, resection of HCC originating in the caudate lobe is challenging, but a plausible guideline enabling safe, curable resection remains unknown. METHODS: We developed an algorithm based on sublocation or size of the tumor and liver function to guide the optimal procedure for resecting HCC in the caudate lobe, consisting of 3 portions (Spiegel, process, and caval). Partial resection was prioritized to remove Spiegel or process HCC, while total resection was aimed to remove caval HCC depending on liver function. RESULTS: According to the algorithm, we performed total (n = 43) or partial (n = 158) resections of the caudate lobe for HCC in 174 of 201 patients (compliance rate, 86.6%), with a median blood loss of 400 (10-4530) mL. Postoperative morbidity (Clavien grade ≥III b) and mortality rates were 3.0% and 0%, respectively. After a median follow-up of 2.6 years (range, 0.5-14.3), the 5-year overall and recurrence-free survival rates were 57.3% and 15.3%, respectively. Total and partial resection showed no significant difference in overall survival (71.2% vs 54.0% at 5 yr; P = 0.213), but a significant factor in survival was surgical margin (58.0% vs 45.6%, P = 0.034). The major determinant for survival was vascular invasion (hazard ratio 1.7, 95% CI 1.0-3.1, P = 0.026). CONCLUSIONS: Our algorithm-oriented strategy is appropriate for the resection of HCC originating in the caudate lobe because of the acceptable surgical safety and curability.

Reconfirmation of the anatomy of the left triangular ligament and the appendix fibrosa hepatis in human livers, and its implication in abdominal surgery.

BACKGROUND: The aim of the present study was to clarify the anatomy between the left triangular ligament (LTL) and the appendix fibrosa hepatis (AFH) in order not to sever the AFH when dissecting the LTL. METHODS: Totals of 43 and 27 cadaveric livers were examined macroscopically and histologically, respectively. RESULTS: The LTL attached itself to the diaphragmatic surface of the AFH through almost all lengths of the AFH. This might be the reason why AFH is so often dissected together with the LTL. There were two types of relation between the LTL and the AFH; in one type, the starting point of the LTL existed on the left liver and in the other type, it was on the AFH. Twenty-five of 27 AFH included remnants of the bile duct and 12 of 25 AFH had comparatively large bile ducts, which was unexceptionally accompanied by the well-developed peribiliary vascular plexus. AFH showed a variety of shapes, such as rectangular (6/43), long triangular (4/43), short triangular (7/43), triangular plus cordlike (11/43), cordlike (12/43) and bifurcated (3/43) types. CONCLUSIONS: As AFH sometimes includes relatively large bile ducts, it is recommended for surgeons to sever the AFH not just simply by electrocautery but by ligating its stump securely.

Irradiation with carbon ion beams induces apoptosis, autophagy, and cellular senescence in a human glioma-derived cell line.

PURPOSE: We examined biological responses of human glioma cells to irradiation with carbon ion beams (C-ions). METHODS AND MATERIALS: A human glioma-derived cell line, NP-2, was irradiated with C-ions. Apoptotic cell nuclei were stained with Hoechst 33342. Induction of autophagy was examined either by staining cells with monodansylcadaverine (MDC) or by Western blotting to detect conversion of microtuble-associated protein light chain 3 (MAP-LC3) (LC3-I) to the membrane-bound form (LC3-II). Cellular senescence markers including induction of senescence-associated beta-galactosidase (SA-beta-gal) were examined. The mean telomere length of irradiated cells was determined by Southern blot hybridization. Expression of tumor suppressor p53 and cyclin/cyclin-dependent kinase inhibitor p21(WAF1/CIP1) in the irradiated cells was analyzed by Western blotting. RESULTS: When NP-2 cells were irradiated with C-ions at 6 Gy, the major population of the cells died of apoptosis and autophagy. The residual fraction of attached cells (<1% of initially irradiated cells) could not form a colony: however, they showed a morphological phenotype consistent with cellular senescence, that is, enlarged and flattened appearance. The senescent nature of these attached cells was further indicated by staining for SA-beta-gal. The mean telomere length was not changed after irradiation with C-ions. Phosphorylation of p53 at serine 15 as well as the expression of p21(WAF1/CIP1) was induced in NP-2 cells after irradiation. Furthermore, we found that irradiation with C-ions induced cellular senescence in a human glioma cell line lacking functional p53. CONCLUSIONS: Irradiation with C-ions induced apoptosis, autophagy, and cellular senescence in human glioma cells.

The caudate processus hepatic vein: a boundary hepatic vein between the caudate lobe and the right liver.

OBJECTIVE: This study was conducted to find the boundary vein indicating the intersegmental plane between the caudate lobe and the adjacent liver segments. SUMMARY BACKGROUND DATA: Major hepatic veins of the human liver commonly run through the intersegmental plane and are widely used for the landmarks to define the boundary of both sides of liver segments. As the caudate lobe is a small independent unit of the liver separate from the right and left livers, the existence of the boundary hepatic vein to the adjacent liver segments has been expected. METHODS: Fifty-four adult cadaveric livers were minutely dissected to elucidate the correlation between the portal vein branches and the hepatic veins on both the caudate lobe and the adjacent liver segments. RESULTS: Among the hepatic veins of the caudate lobe, the caudate processus hepatic vein entering the inferior vena cava at hepatic hilum runs in the segmental plane between the caudate processus and the right liver. Three types of the caudate processus hepatic vein directly entering the inferior vena cava and 1 type of the exceptional hepatic vein that was the tributary of the right hepatic vein were observed. They drained the blood of the caudate processus and a part of the right liver, respectively. CONCLUSIONS: The caudate processus hepatic vein is one of the candidates of the hepatic vein indicating the boundary between the caudate lobe and the adjacent liver segments. New procedures will be developed on the liver surgeries by acquiring the anatomic features of this vein.

Close relation between the inferior vena cava ligament and the caudate lobe in the human liver.

BACKGROUND/PURPOSE: This study was conducted to clarify the real relation between the inferior vena cava (IVC) ligament and the caudate lobe in the human liver and also to elucidate their surgical importance in liver surgery. METHODS: Specimens obtained from 20 adult cadaveric livers were submitted for the study. Histological structures of the IVC ligament and its relationship to the caudate lobe and the IVC were microscopically investigated. RESULTS: The IVC ligament was a broad membranous connective tissue bridging the left and right side edges of the caval groove in which the IVC was embedded. At both edges of the caval groove, the IVC ligament was continuously transformed from the Glisson's capsules of the caudate and right lobes. The component of the portal triad, which originated from that of caudate lobe, and lymphatics were distributed in the IVC ligament without exception and ectopic hepatocytes existed in it in 4 of the 20 cases. CONCLUSIONS: A close relation between the IVC ligament and the caudate lobe was confirmed. The findings suggested that the IVC ligament is a kind of degenerated hepatic tissue. When dissecting it, surgeons should manipulate it carefully to prevent unexpected bleeding and bile leakage.

Morphogenesis of an anomalous ligamentum venosum terminating in the superior left hepatic vein in a human liver.

BACKGROUND/PURPOSE: We aimed to clarify the morphogenesis of an anomalous ligamentum venosum terminating in the trunk of the superior left hepatic vein, because the ligamentum venosum ordinarily terminates into the root of the left hepatic vein or directly into the inferior vena cava. METHODS: We examined an anomalous ligamentum venosum found in the cadaveric liver of an 84-year-old Japanese woman. RESULTS: The ligamentum venosum in this liver was not found in the usual course, the fissure for the ligamentum venosum. It lay on the posterior surface of the liver, connecting the left branch of the portal vein and the trunk of a small left hepatic vein. The small left hepatic vein draining the cranio-dorsal part of the lateral segment of the liver was revealed to be a superior left hepatic vein. This type of anomaly was found only in this 1 liver, among 125 cadaveric livers that were dissected. CONCLUSIONS: Taking previous reports into consideration, the morphogenesis of the anomalous ligamentum venosum in the present case may be explained as being due to the persistence of the right half of the subdiaphragmatic anastomosis, which receives the blood from the ductus venosus in the embryonal period.

Activin A augments vascular endothelial growth factor activity in promoting branching tubulogenesis in hepatic sinusoidal endothelial cells.

BACKGROUND/AIMS: The production of activin A is markedly up-regulated in hepatocytes after partial hepatectomy. This factor tonically inhibits growth of hepatocytes but little is known about its effect on sinusoidal endothelial cells (SEC). In the present study, we investigated whether or not activin A affects growth and differentiation of SEC. METHODS: Growth and survival of SEC were measured in monolayer culture. Capillary formation was studied using SEC cultured in a collagen gel. RESULTS: SEC could not survive in the absence of vascular endothelial growth factor (VEGF). Activin A had a small effect on prevention of cell death and also enhanced anti-apoptotic action of VEGF. In addition, activin A and VEGF acted synergistically to stimulate cell growth of SEC. In the collagen gel, VEGF induced capillary formation of SEC. Activin A had little effect on branching tubulogenesis by itself but markedly enhanced tubular formation induced by VEGF. Finally, VEGF induced the expression of activin A and activin A increased the expression of VEGF receptors in cultured SEC. CONCLUSIONS: Activin A augments VEGF activity in promoting growth and tubulogenesis of SEC.

Long-term survival after hepatectomy for large metastatic breast cancer: a case report.

Long-term survival after the resection for liver metastasis from breast cancer is rare. We report on a 49-year-old woman who has been alive and well for 12 years following hepatic resection for metastatic breast cancer. Fourteen years before, the patient underwent a radical mastectomy for cancer of the right breast. One year after the operation the patient presented with right upper quadrant pain and a large isolated right lobe liver metastasis was found. Initially, it was too large to be treated by hepatectomy. Thus, intra-arterial one-shot injection of 20 mg of mitomycin C mixed with 4 mL of lipiodol was given three times at 1-month intervals and was followed by 5-fluorouracil (250 mg) and mitomycin C (2 mg) administered 9 times at 2-week intervals through the implanted port. Additionally, 150 mg of 5-fluorouracil and 1200 mg of medroxiprogesterone acetate were orally administered for 5 months. These therapies led to a remarkable reduction in tumor size and the metastasis was safely resected by an extended right hepatic lobectomy. The specimen was completely necrotic and histologically no viable tumor cell was observed. In the present case, the aggressive preoperative chemo- and hormonal therapies might be significant in making a contribution to longer survival.

Reproposal for Hjortsjo's segmental anatomy on the anterior segment in human liver.

BACKGROUND: A minimum, but necessary amount, of cancer-containing liver tissue is to be excised in patients who have poor liver function. To achieve that goal of excision, a limited hepatic resection has been carried out. However, performing subsegmentectomy of the anterior segment according to the conventional segmental anatomy introduced by Healey and Schroy or Couinaud is difficult. Because the transverse border between segments 5 and 8 was drawn as an imaginary line through the right portal vein, there is no anatomical structure indicating this border. HYPOTHESIS: Hjortsjo divided the anterior segment into 2 vertical segments according to the fissure in which a hepatic vein coursed. By including Hjortsjo's concept of segmental anatomy, new procedures will be added to hepatic surgery. DESIGN: Sixty-five cadaveric livers were dissected to confirm Hjortsjo's concept of segmental anatomy by investigating the vertical fissure that divides the anterior segment into 2 areas, concerning the relation between portal segmentation and the hepatic venous system of the anterior segment. RESULTS: The territories of the third-order portal branches of the anterior segment were divided into 2 (ventral and dorsal) areas with a vertical fissure and in its intersubsegmental plane, an independent hepatic vein, or a first-order branch of the middle or the right hepatic vein coursed. CONCLUSIONS: These findings confirmed the certainty of Hjortsjo's concept of segmental anatomy of the anterior segment. This is relevant for developing new procedures in hepatic surgery. Its reproposal is opportune for adding it as another concept to the conventional segmental anatomy.

Snowboarding splenic injury: four case reports.

With the rapidly increasing number of snowboarders, the incidence of injuries has recently become higher. From 1994 to 1995, we encountered four snowboarders with splenic injuries in one season. In three of the four patients the splenic injuries were caused by striking the abdomen with their own elbow when falling by themselves, of which emergent splenectomy was required in two patients. In the other one the collision with another snowboarder caused the splenic injury and splenorrhaphy was performed. Because snowboarders have both feet fixed on a board and do not have poles, they are prone to fall on the left upper limb in the proceeding direction, resulting in the striking of the left upper abdomen. Because in snowboarders splenic injury is caused mostly by a blow from their own left elbow at the time of falling, informing the mechanisms of splenic injuries will serve a speedy correct diagnosis for the doctors.