Clinical significance of anatomical variant of the left hepatic artery for perihilar cholangiocarcinoma applied to right-sided hepatectomy

Impact of the course of the segment 4 hepatic artery on proximal ductal margin status in right hepatectomy for perihilar cholangiocarcinoma

BACKGROUND

The relationship between the course of the segment 4 hepatic artery and proximal ductal margin status in the right hepatectomy (H15678-B) for perihilar cholangiocarcinoma is unclear. This study aimed to evaluate proximal ductal margin status according to the course of the segment 4 hepatic artery in patients with perihilar cholangiocarcinoma treated with right hepatectomy.

METHODS

Consecutive patients with perihilar cholangiocarcinoma who underwent a right hepatectomy between January 2006 and August 2021 were retrospectively reviewed. The course of the segment 4 hepatic artery was classified based on the positional relationship with the umbilical portion of the left portal vein into R-UP and L-UP types. The R-UP type had the segment 4 hepatic artery running along the right caudal position of the umbilical portion of the left portal vein, whereas the L-UP type had the segment 4 hepatic artery running along the left cranial position of the umbilical portion of the left portal vein, with or without another branch running along the right caudal position of the umbilical portion of the left portal vein. Proximal ductal margin status after the right hepatectomy was compared between types.

RESULTS

Among 102 patients, 72 (70.5%) were R-UP type, and 30 (29.5%) were L-UP type. Rates of negative proximal ductal margin were higher with the L-UP type (27/30, 90.0%) than with the R-UP type (51/72, 70.8%; P = .04). On multivariate analysis, Bismuth-Corlette type II and IIIa (risk ratio 4.13, 95% confidence interval 1.52-11.5; P = .005) and L-UP type (risk ratio 4.03, 95% confidence interval 1.18-18.8; P = .04) were independent predictors of negative proximal ductal margin after a right hepatectomy for perihilar cholangiocarcinoma.

CONCLUSION

For the course of the segment 4 hepatic artery, L-UP type rather than R-UP type might be anatomically advantageous for achieving negative proximal ductal margin in a right hepatectomy for perihilar cholangiocarcinoma.

Surgical implications of the confluence patterns of the left intrahepatic bile ducts in right hepatectomy for perihilar cholangiocarcinoma

BACKGROUND

Although the most important goal in surgery for perihilar cholangiocarcinoma (PHC) is to achieve tumor-free proximal ductal margins, little is known about the implications of confluence patterns of the left intrahepatic bile ducts for the proximal ductal margin status in right hepatectomy (RH) for PHC.

METHODS

Of 203 patients who underwent surgical resection for PHC with curative intent, confluence patterns of the left intrahepatic bile duct were evaluated in 94 consecutive patients who underwent RH, and they were classified into the following two types: normal type: the bile duct of segment 4 (B4) drained into the common trunk of the bile ducts of segment 2 (B2) and segment 3 (B3) at the right side of the umbilical portion of the left portal vein to form the left hepatic duct; and hepatic confluence type: B2 entered the common trunk of B3 and B4 at the hepatic confluence or B4 entered the common trunk of B2 and B3 at the hepatic confluence. The proximal ductal margin status following RH was compared between the two types of confluence patterns.

RESULTS

Of 94 consecutive patients, 69 (73%) were the normal type, and 25 (27%) were the hepatic confluence type. There were no significant differences in patients' characteristics, surgical characteristics, surgical outcomes, and histopathological features between the two groups. However, in patients with Bismuth-Corlette type II and IIIa PHC, the achievement rates of negative proximal ductal margins at the first dividing line were significantly higher in the hepatic confluence type group than in the normal type group (16/16 [100%] vs 34/52 [65%], respectively; P = .007).

CONCLUSIONS

Confluence patterns of the left intrahepatic bile ducts might affect proximal ductal margin status in RH for PHC.

Precision Liver Resection: Three-Dimensional Reconstruction Combined with Fluorescence Laparoscopic Imaging

Liver surgery has entered the era of precision surgery. Therefore, how to optimize the resection of lesions and reduce the unnecessary time of liver ischemia and hypoxia have become the focus. A total of 11 patients who underwent fluorescence laparoscopic liver mass resection and preoperative three-dimensional (3D) reconstruction between August 2018 and July 2020 were evaluated. Liver cirrhosis occurred in 3 patients. The mean intraoperative blood loss was 166.8 ± 105.7 mL. The average length of the operation time was 152.0 ± 45.3 minutes. The average intraoperative hilar occlusion time was 9.3 minutes (except for hilar cholangiocarcinoma). The liver function of all patients, except patients with hilar bile duct carcinoma, returned to the preoperative level at 72 hours, and no serious complications occurred. 3D reconstruction combined with fluorescence laparoscopic imaging is safe and effective for precision liver resection.

Liver Transection-First Approach in Left Trisectionectomy for Perihilar Cholangiocarcinoma

Left trisectionectomy [(LT) resection of segments 2, 3, 4, 5, 8, and 1] for perihilar cholangiocarcinoma is still a challenging procedure with high postoperative morbidity and mortality. To perform LT safely, the liver transection-first approach was developed. In this approach, liver transection is started without dividing the right anterior hepatic artery (RAHA) and right anterior portal vein (RAPV). After the completion of liver transection, the RAHA and RAPV, which run into the future resected liver, can be easily identified and divided under the wide surgical field at the hepatic hilus. The liver transection-first approach appears to be safer than the conventional LT, leading to less postoperative morbidity and mortality.

Precise right hemihepatectomy for the treatment of hepatocellular carcinoma guided by fusion ICG fluorescence imaging

To evaluate the clinical significance of fusion indocyanine green (ICG) fluorescence imaging in precise right hemihepatectomy for the treatment of hepatocellular carcinoma (HCC). 47 patients with HCC who underwent right hemihepatectomy were retrospectively analyzed. 18 of them guided by fusion ICG fluorescence imaging (FIGFI) while 29 patients underwent conventional right hepatectomy without guidance. Compared to the patients with conventional treatment, the intraoperative blood loss of the patients with guided surgery was significantly less, and no transfusion and hepatic occlusion were performed during the operation. Liver function recovery faster in guided group. The incidence of postoperative complications is also lower, and the recurrence rate in one year is significantly reduced. ICG fluorescence range of 18 patients in liver surface was consistent with the ischemic line, and their postoperative liver cross-sections were clearly demarcation. There were no significant differences in the mean operation time, blood loss, postoperative hospital stays, cases of blood transfusion, complication rate, or postoperative peak volume of ALT and TB between positive or negative staining groups. Pathology results of all patients demonstrated HCC and negative margins, and microvascular invasion occurred in 8 cases. The average follow-up time of 18 patients was 16.7 months, and recurrence was found in 5 cases after surgery. FIGFI could guide the anatomical right hepatectomy with real -time increased radical rate, accuracy and safety for the treatment of HCC, and therefore showed a promising prospect.

Outcomes of left trisectionectomy and right hepatectomy for perihilar cholangiocarcinoma

BACKGROUND

Right hepatectomy (RH) is the standard surgical procedure for perihilar cholangiocarcinoma (PHC) with right-sided predominance in many centers. Although left trisectionectomy (LT) is aggressively performed for PHC with left-sided predominance in high-volume centers, the surgical and survival outcomes of LT are unclear. Therefore, this study aimed to compare the outcomes of LT and RH for PHC.

METHODS

Consecutive patients who underwent surgical resection for PHC at Chiba University Hospital from 2008 to 2016 were retrospectively reviewed. The outcomes of patients with PHC who underwent LT were compared with those who underwent RH following one-to-one propensity score matching.

RESULTS

Of 171 consecutive PHC resection patients, 111 were eligible for the study; 41 (37%) underwent LT, and 70 (63%) underwent RH. In a matched cohort (LT: n = 27, RH: n = 27), major complication rates (67% vs. 52%; p = 0.42), 90-day mortality rates (15% vs. 0%; p = 0.11) and R0 resection rates (56% vs. 44%; p = 0.58) were similar in both groups. The 3-year recurrence-free survival rates (27% vs. 47%; p = 0.27) and overall survival rates (45% vs. 60%; p = 0.17) were also similar in both groups.

CONCLUSIONS

In patients with PHC, LT could achieve similar surgical and survival outcomes as RH.

Impact of Biliary Drainage on Multidetector-Row Computed Tomography on R0 Resection of Perihilar Cholangiocarcinoma

BACKGROUND

Although multidetector-row computed tomography (MDCT) before biliary drainage is useful for the assessment of the resectability of perihilar cholangiocarcinoma (PHC), the impact of biliary drainage on MDCT images before surgical resection for PHC has been poorly studied, and its possible consequences for R0 resection of PHC remain unclear. This study was performed to compare the surgical outcomes of patients with PHC who underwent MDCT before versus after biliary drainage.

METHODS

All consecutive patients who underwent major hepatectomy extending to segment 1 with extrahepatic bile duct resection for PHC from 2009 to 2016 were retrospectively evaluated. R0 resection was defined as no residual cancer at all surgical margins. Patients with pathological stage IV PHC were excluded.

RESULTS

Of 142 patients who underwent major hepatectomy, 108 were eligible for this study. Of these 108 patients, 64 (59%) and 44 (41%) underwent MDCT before and after biliary drainage, respectively. The total bilirubin concentration at presentation was lower in patients who underwent MDCT before than after biliary drainage (4.1 ± 5.9 vs. 8.0 ± 7.1 mg/ml, respectively; p = 0.002). Although there were no significant differences in the surgical characteristics or pathological stages between the two groups, R0 resection was more frequently achieved in patients who underwent MDCT before than after biliary drainage [46/64 (72%) vs. 22/44 (50%), respectively; p = 0.03]. On multivariate analysis, MDCT before biliary drainage was independently associated with R0 resection of PHC (risk ratio: 2.38, 95% CI 1.05-5.41; p = 0.04).

CONCLUSIONS

In selected patients, MDCT should be performed before biliary drainage to achieve R0 resection of PHC.

Radiologic evaluation of vasculobiliary anatomy in the umbilical fissure

BACKGROUND

Preoperative evaluation of vasculobiliary anatomy in the umbilical fissure (U-point) is pivotal for perihilar cholangiocarcinoma (PCCA) applied to right-sided hepatectomy. The purpose of our study was to review the vasculobiliary anatomy in the U-point using three-dimensional (3D) reconstruction technique, to investigate the diagnostic ability of 2D scans to evaluate anatomic variations, and to discuss its surgical implications.

METHODS

A retrospective study of 159 patients with Bismuth type I, II, and IIIa PCCA, who received surgery at our institution from November 2012 to September 2016, was conducted. Anatomic structures were assessed using multidetector computed tomography (MDCT) by one hepatobiliary surgeon, whereas 3D images were reconstructed by an independent radiologist. Normal confluence pattern of left biliary system was defined as the left medial segmental bile duct (B4) joining the common trunk of segment II (B2) and segment III (B3) ducts, whereas aberrant confluence patterns were classified into 3 types: type I, triple confluence of B2, B3, and B4; type II, B2 draining into the common trunk of B3 and B4; type III, other patterns. Surgical anatomy of B4 was classified into the central, peripheral, and combined type according to its relation to the hepatic confluence. The lengths from the bile duct branch of Spiegel's lobe (B1l) to the orifice of B4 and the junction of B2 and B3 were measured on 3D images. The anatomy of left hepatic artery (LHA) was classified according to different origins and the spatial relationship related to the U-point.

RESULTS

3D reconstruction revealed that normal confluence pattern of left biliary system was observed in 71.1% (113/159) of all patients, and variant patterns were type I in 11.9% (19/159), type II in 12.6% (20/159), and type III in 4.4% (7/159). The length from B1l to the junction of B2 and B3 was 12.1 ± 3.1 mm in type I variation, which was significantly shorter than that in normal configuration (30.0 ± 6.8 mm, P < 0.001) but significantly longer than that in type II variation (9.6 ± 3.4 mm, P = 0.019). Surgical anatomy of B4: the peripheral type was most commonly seen (74.2%, 118/159), followed by central type (15.7%, 25/159) and combined type (10.1%, 16/159). The distance between the B1l and B4 was 8.4 ± 2.4 mm in central and combined type, which was significantly shorter than that in peripheral type (14.5 ± 4.1 mm, P < 0.001). A replaced or accessory LHA from the left gastric artery was present in 6 (3.8%) and 9 (5.7%) patients, respectively. LHA running along the left caudal position of U-point was present in 143 cases (89.9%), along the right cranial position of U-point in nine cases (5.7 %), and combined position in seven cases (4.4%). Interobserver agreement of two imaging modalities was almost perfect in biliary confluence pattern (kappa = 0.90; 95% confidence interval: 0.79-1.00), substantial in surgical anatomy of B4 (kappa = 0.74; 95% confidence interval: 0.62-0.86), and perfect in LHA (kappa = 1.00).

CONCLUSIONS

Thoroughly understanding the imaging characters of surgical anatomy in the U-point may be benefit for preoperative evaluation of PCCA by successive review of 2D images alone, whereas 3D reconstruction technique allows detailed hepatic anatomy and individualized surgical planning for advanced cases.