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

Evaluation of SR-DLR in low-dose abdominal CT: superior image quality and noise reduction

OBJECTIVES

To evaluate the effectiveness of super-resolution deep learning reconstruction (SR-DLR) in low-dose abdominal computed tomography (CT) imaging compared with hybrid iterative reconstruction (HIR) and conventional deep learning reconstruction (cDLR) algorithms.

METHODS

We retrospectively analyzed abdominal CT scans performed using a low-dose protocol. Three different image reconstruction algorithms-HIR, cDLR, and SR-DLR-were applied to the same raw image data. Objective evaluations included noise magnitude and contrast-to-noise ratio (CNR), as well as noise power spectrum (NPS) and edge rise slope (ERS). Subjective evaluations were performed by radiologists, who assessed image quality in terms of noise, artifacts, sharpness, and overall diagnostic utility.

RESULTS

Raw CT image data were obtained from 35 patients (mean CTDIvol 11.0 mGy; mean DLP 344.8 mGy/cm). cDLR yielded the lowest noise levels and highest CNR (p < 0.001). However, SR-DLR outperformed cDLR in terms of noise texture and resolution, achieving the lowest NPS peak and highest ERS (p < 0.001 and p = 0.005, respectively). Subjectively, SR-DLR was rated highest across all categories, including noise, artifacts, sharpness, and overall image quality, with statistically significant differences compared to cDLR and HIR (p < 0.001).

CONCLUSION

SR-DLR was the most effective reconstruction algorithm for low-dose abdominal CT imaging, offering superior image quality and noise reduction compared to cDLR and HIR. This suggests that SR-DLR can enhance the reliability and diagnostic accuracy of abdominal imaging, particularly in low-dose settings, making it a valuable tool in clinical practice.

The impact of positive resection margin in perihilar cholangiocarcinoma, ductal margin vs radial margin

INTRODUCTION

Resection margin status is the important prognostic factor in resected perihilar cholangiocarcinoma (pCCA). Although the impact of ductal margin (DM) was reported in many studies, the influence of radial margin (RM) is unclear. This study aims to investigate the effect of positive RM on survival.

METHODS

Patients with pCCA underwent curative resection between 2013 and 2018 were retrospectively reviewed. Resection margin status was divided into negative resection margin (R0) and positive resection margin (R1); positive RM alone (RM+) and positive DM with or without positive RM (DM+).

RESULTS

Of the 167 pCCA patients, 62 (37.1%) had R1 margin. Among 62 R1 patients; 17 (27.4%) had positive DM alone, 20 (32.3%) had positive RM alone and 25 (40.3%) had both positive DM and RM. The R1 patients had a significantly greater number of lymph node metastasis (LNM) and advanced tumor staging than R0 patients, however there was no difference between the RM + and DM + patients. The median survival time of patients with RM + was significantly poorer than R0 patients (13.8 vs. 24.5 months; p < 0.001, respectively) and similar to the DM + patients (9.1 months, p = 0.556). However, in patients with LNM, those who underwent R0 resection had no statistically significant difference in survival outcomes compared to those with R1 resection.

CONCLUSION

Positive resection margin remains the important prognostic factor, and positive RM is common in these patients. Positive RM also had a comparable effect on survival as positive DM. As a result, in pCCA, surgical resection should target both RM and DM.

Preoperative CT and MRI assessment of the longitudinal tumor extent of extrahepatic bile duct cancer after biliary drainage

PURPOSE

To examine the diagnostic performance for the longitudinal extent of extrahepatic bile duct (EHD) cancer on computed tomography (CT) after biliary drainage (BD) and investigate the appropriate timing of magnetic resonance imaging (MRI) acquisition.

METHODS

This retrospective study included patients who underwent curative-intent surgery for EHD cancer and CT pre- and post-BD between November 2005 and June 2021. The biliary segment-wise longitudinal tumor extent was evaluated according to the 2019 Korean Society of Abdominal Radiology consensus recommendations, with pre-BD CT, post-BD CT, and both pre- and post-BD CT. The performance for tumor detectability was compared using generalized estimating equation (GEE) method. When preoperative MRI was performed, patients were divided into two subgroups according to the timing of MRI with respect to BD, and the performance of MRI obtained pre- and post-BD was compared.

RESULTS

In 105 patients (mean age: 67 ± 8 years; 74 men and 31 women), the performance for tumor detectability was superior using both CT scans compared with using post-BD CT alone (reader 1: sensitivity, 72.6% vs. 64.6%, P < 0.001; specificity, 96.9% vs. 94.8%, P = 0.063; reader 2: sensitivity, 77.2% vs. 72.9%, P = 0.126; specificity, 97.5% vs. 94.2%, P = 0.003), and it was comparable with using pre-BD CT alone. In biliary segments with a catheter, higher sensitivity and specificity were observed using both CT scans than using post-BD CT (reader 1: sensitivity, 74.4% vs. 67.5%, P = 0.006; specificity, 92.4% vs. 88.0%, P = 0.068; reader 2: sensitivity, 80.5% vs. 74.4%, P = 0.013; specificity, 94.3% vs. 88.0%, P = 0.016). Post-BD MRI (n = 30) exhibited a comparable performance to pre-BD MRI (n = 55) (reader 1: sensitivity, 77.9% vs. 75.0%, P = 0.605; specificity, 97.2% vs. 94.9%, P = 0.256; reader 2: sensitivity, 73.2% vs. 72.6%, P = 0.926; specificity, 98.4% vs. 94.9%, P = 0.068).

CONCLUSION

Pre-BD CT provided better diagnostic performance in the preoperative evaluation of EHD cancer. The longitudinal tumor extent could be accurately assessed with post-BD MRI, which was similar to pre-BD MRI.

CLINICAL SIGNIFICANCE

The acquisition of pre-BD CT could be beneficial for the preoperative evaluation of EHD cancer when BD is planned. Post-BD MRI would not be significantly affected by BD in terms of the diagnostic performance of the longitudinal tumor extent.

Survival outcomes of surgical resection in perihilar cholangiocarcinoma in endemic area of O. Viverrini, Northeast Thailand

BACKGROUND

Perihilar cholangiocarcinoma (pCCA) is an intractable malignancy and remains the most challenge for surgeon. This study aims to investigate survival outcomes and prognostic factors in pCCA patient.

METHODS

From October 2013 to December 2018, 240 consecutive patients with pCCA underwent surgical exploration were retrospectively reviewed. The clinicopathological parameters and surgical outcomes were extracted. Patients were divided into two groups: unresectable and resectable group. The restricted mean survival time between two groups were analyzed. Factors associated with overall survival in resectable group were explored with multivariable Cox regression analysis.

RESULTS

Of the 240 patients, 201 (83.75%) were received surgical resection. The survival outcomes of resectable group were better than unresectable group significantly. The restricted mean survival time difference were 0.5 (95%CI 0.22-0.82) months, 1.8 (95%CI 1.15-2.49) months, 4.7 (95%CI 3.58-5.87) months, and 9.1 (95%CI 7.40-10.78) months at four landmark time points of 3, 6, 12 and 24 months, respectively. The incidence of major complications and 90-day mortality in resectable group were 35.82% and 11.44%, respectively. Multivariable analysis revealed that Bismuth type IV (HR:4.43, 95%CI 1.85-10.59), positive resection margin (HR:4.24, 95%CI 1.74-10.34), and lymph node metastasis (HR:2.29, 95%CI 1.04-4.99) were all independent predictors of long-term survival. For pM0, R0 and pN0 patients, the median survival time was better than pM0, R1 or pN1/2 patients and pM0, R1 and pN1/2 patients (32.4, 10.4 and 4.9 months, respectively; p < 0.001) CONCLUSION: Surgical resection increased survival in pCCA. Bismuth type IV, positive resection margin and lymph node metastasis were independent factors for long-term survival.

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.

Prognostic impact of proximal ductal margin status in perihilar cholangiocarcinoma according to the presence or absence of lymph node metastasis

BACKGROUND

Although both proximal ductal margin status and lymph node metastasis status influence the survival of patients with perihilar cholangiocarcinoma, the effect of proximal ductal margin status on survival according to lymph node metastasis status is unclear. The aim of this study was, thus, to evaluate the prognostic impact of proximal ductal margin status in perihilar cholangiocarcinoma according to the presence or absence of lymph node metastasis.

METHODS

Consecutive patients with perihilar cholangiocarcinoma who underwent major hepatectomy between June 2000 and August 2021 were retrospectively reviewed. Patients with Clavien-Dindo grade V complications were excluded from the analysis. Overall survival was assessed according to the combination of lymph node metastasis and proximal ductal margin status.

RESULTS

Of the 230 eligible patients, 128 (56%) were lymph node metastasis negative, and 102 (44%) were lymph node metastasis positive. Overall survival was significantly better in lymph node metastasis negative than lymph node metastasis positive patients (P < .0001). Of the 128 lymph node metastasis-negative patients, 104 (81%) were proximal ductal margin negative, and 24 (19%) were proximal ductal margin positive. In lymph node metastasis-negative patients, overall survival was worse in the proximal ductal margin positive than the proximal ductal margin negative group (P = .01). Of the 102 lymph node metastasis-positive patients, 72 (71%) were proximal ductal margin negative and 30 (29%) were proximal ductal margin positive. In these patients, overall survival was similar between the 2 groups (P = .10).

CONCLUSION

In patients with perihilar cholangiocarcinoma, the prognostic impact of proximal ductal margin positivity on survival might differ according to the presence or absence of lymph node metastasis.

Preoperative Diagnosis of Lymph Node Metastasis of Perihilar Cholangiocarcinoma Using Diffusion-Weighted Magnetic Resonance Imaging

INTRODUCTION

Although the prognosis of patients with resected perihilar cholangiocarcinoma (PHC) with histological lymph node metastasis (LNM) is poor, preoperative prediction of LNM is difficult. This study aimed to evaluate the diagnostic performance of diffusion-weighted magnetic resonance imaging (DWI) for LNM of PHC.

METHOD

Consecutive patients who underwent surgical resection of PHC between January 2012 and May 2020 were retrospectively reviewed. The lymph node (LN) area (mm²) and apparent diffusion coefficient (ADC) value ( × 10^-3 mm²/s) of pericholedochal LNs were measured by DWI. The characteristics of the patients and the LNs were evaluated according to the histological presence or absence of regional LNM. Univariate and multivariate analyses were performed to identify the predictors of LNM of PHC.

RESULTS

Of the 93 eligible patients, 49 (53%) were LNM positive and 44 (47%) were LNM negative. Although the characteristics of the patients were similar between the two groups, the mean ADC value was significantly lower in the LNM positive group than in the LNM negative group. On multivariate analysis, mean ADC value ≤1.80 × 10^-3 mm²/s was independently associated with LNM of PHC (risk ratio: 12.5, 95% confidence interval: 3.05-51.4; p = 0.0004). The sensitivity, specificity and accuracy of mean ADC values ≤ 1.80 × 10^-3 mm²/s for predicting LNM of PHC were 94%, 55% and 75%, respectively.

CONCLUSIONS

DWI might be useful for the preoperative diagnosis of LNM of PHC.

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.

Clinical implication of ICG test in major hepatectomy for biliary tract cancer

BACKGROUND

Major hepatectomy with bile duct resection (BDR) is associated with severe postoperative complications; therefore, evaluation of preoperative liver function is important. However, little is known about mechanisms of increased severe complications in patients with poor liver function. The aim of this study was to evaluate whether indocyanine green retention rate after 15 minutes of injection (ICG-R15) is useful for predicting the risk of severe postoperative complications in this operation, and to reveal the mechanisms of increasing severe complications by focusing on immune function and liver regeneration after hepatectomy.

METHODS

Patients receiving major hepatectomy with BDR between 2000 and 2017 were retrospectively reviewed. Severe postoperative complications were defined as Clavien-Dindo grade ≥IV.

RESULTS

In 284 patients undergoing major hepatectomy with BDR, ICG-R15 was correlated with severe postoperative complications, with cut-off value of 11.8%. In brief, the incidences of hyperbilirubinemia, coagulopathy, liver failure, respiratory failure, severe complications, and mortality were higher in the high ICG-R15 group. Moreover, high ICG-R15 (≥11.8%) was an independent factor for predicting severe complications after major hepatectomy with BDR. Immune dysfunction in the early phase after operation, prolonged postoperative immunosuppression, and delayed liver regeneration were reasons for increasing severe postoperative complications in patients with high ICG-R15.

CONCLUSIONS

High ICG-R15 is an independent risk factor for severe complications after major hepatectomy with BDR, and its cut-off value is 11.8%. Compromised condition and delayed liver regeneration induced by immune dysfunction are reasons of increased severe postoperative complications in patients with high ICG-R15.

Practical review for diagnosis and clinical management of perihilar cholangiocarcinoma

Cholangiocarcinoma (CCC) is the most aggressive malignant tumor of the biliary tract. Perihilar CCC (pCCC) is the most common CCC and is burdened by a complicated diagnostic iter and its anatomical location makes surgical approach burden by poor results. Besides its clinical presentation, a multimodal diagnostic approach should be carried on by a tertiary specialized center to avoid miss-diagnosis. Preoperative staging must consider the extent of liver resection to avoid post-surgical hepatic failure. During staging iter, magnetic resonance can obtain satisfactory cholangiographic images, while invasive techniques should be used if bile duct samples are needed. Consistently, to improve diagnostic potential, bile duct drainage is not necessary in jaundice, while it is indicated in refractory cholangitis or when liver hypertrophy is needed. Once resecability criteria are identified, the extent of liver resection is secondary to the longitudinal spread of CCC. While in the past type IV pCCC was not considered resectable, some authors reported good results after their treatment. Conversely, in selected unresectable cases, liver transplantation could be a valuable option. Adjuvant chemotherapy is the standard of care for resected patients, while neoadjuvant approach has growing evidences. If curative resection is not achieved, radiotherapy can be added to chemotherapy. This multistep curative iter must be carried on in specialized centers. Hence, the aim of this review is to highlight the main steps and pitfalls of the diagnostic and therapeutic approach to pCCC with a peculiar attention to type IV pCCC.

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.

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.