Liver resection for non-colorectal metastases

Indication model for laparoscopic repeat liver resection in the era of artificial intelligence: machine learning prediction of surgical indication

BACKGROUND

Laparoscopic repeat liver resection (LRLR) is still a challenging technique and requires a careful selection of indications. However, the current difficulty scoring system is not suitable for selecting indications. The purpose of this study is to develop the indication model for LRLR using machine learning and to identify factors associated with open conversion (OC).

METHODS

Patients who underwent repeat hepatectomy (2017-2021) at Samsung Medical Center 2021 were investigated. Multiple indication models were developed using machine learning techniques (random forest, SVM, XGB) and logistic regression. The predictive performance of these models was compared, and risk factors associated with OC were analyzed.

RESULTS

Among 221 patients (110 LRLR, 111 ORLR), the ORLR group had a higher previous open approach rate (75.7% vs. 38.2%, p<0.001). Twice previous abdominal surgery was the only independent OC risk factor (OR 6.56, p=0.009). The indication model showed moderate predictive power (random forest AUC=0.779, logistic regression AUC=0.725, p=0.710). Important variables were previous laparoscopic approach, present subsegmentectomy, and left-sided tumor location.

CONCLUSION

The performance of the indication model for LRLR showed moderate predictive power in both machine learning and logistic regression. The important variables for LRLR were previous laparoscopic approach, present subsegmentectomy, and left side location.

Surgery for liver metastases from primary melanoma: a systematic review and meta-analysis

BACKGROUND

Historically , liver metastases due to melanoma have been associated with dismal prognosis. Moreover, the actual survival benefit from the treatment of melanoma liver metastases is still controversial. Hence, this study aims to evaluate the difference in surgical versus non-surgical options for melanoma liver metastases.

METHODS

Four databases (PubMed, EMBASE, Scopus, and Cochrane Library) were searched from inception to July 17, 2022. Studies were included if they compared outcomes between surgical and non-surgical treatment for patients with liver metastases from resectable melanoma. Meta-analyses were performed for the outcomes of 1-year, 2-year, 3-year and 5-year OS. Sensitivity analyses were performed for outcomes with substantial statistical heterogeneity. To account for possible moderators that might contribute to statistical heterogeneity, univariate meta-regression with mixed-effects models and subgroup analyses were conducted for the outcome of 2-year OS.

RESULTS

The search yielded 6610 articles; 13 studies were included in our analysis. Meta-analyses showed that survival outcomes were in favour of patients undergoing surgery as compared to non-surgery: 1-year OS (HR = 0.29, 95%CI 0.19-0.44, p < 0.00001), 2-year OS (HR = 0.19, 95%CI 0.09-0.38, p < 0.00001), 3-year OS (HR = 0.07, 95%CI 0.03-0.19, p < 0.00001) and 5-year OS (HR = 0.07, 95%CI 0.02-0.22, p < 0.00001). All included studies were of high quality. There was moderate-to-high statistical heterogeneity. Findings were robust to sensitivity analyses. Subgroup analyses and univariate meta-regression revealed neoadjuvant therapy and age as statistically significant subgroup and moderator respectively.

CONCLUSIONS

This study suggests that surgical treatment of melanoma liver metastases could offer better OS outcomes compared with non-surgical treatment.

Is hepatic resection justified for non-colorectal non-neuroendocrine liver metastases? A systematic review and meta-analysis

BACKGROUND

Hepatic resection (HR) is effective for colorectal or neuroendocrine liver metastases. However, the role of HR for non-colorectal non-neuroendocrine liver metastases (NCNNLM) is unknown. This study aims to perform a systematic review and meta-analysis on long-term clinical outcomes after HR for NCNNLM.

METHODS

electronic search was performed to identify relevant publications using PRISMA and MOOSE guidelines. Primary outcomes were 3- and 5-year overall survival (OS) and disease-free survival (DFS). Secondary outcomes were post-operative morbidity and 30-day mortality.

RESULTS

There were 40 selected studies involving 5696 patients with NCNNLM undergone HR. Pooled data analyses showed that the 3- and 5-year OS were 40% (95% CI 0.35-0.46) and 32% (95% CI 0.29-0.36), whereas the 3- and 5-year DFS were 28% (95% CI 0.21-0.36) and 24% (95% CI 0.20-0.30), respectively. The postoperative morbidity rate was 28%, while the 30-day mortality was 2%. Subgroup analysis on HR for gastric cancer liver metastasis revealed the 3-year and 5-year OS of 39% and 25%, respectively.

CONCLUSIONS

HR for NCNNLM may achieve satisfactory survival outcome in selected patients with low morbidities and mortalities. However, more concrete evidence from prospective study is warrant in future.

A prospective randomized trial comparing microwave and radiofrequency ablation for the treatment of liver metastases using a dual ablation system ─ The Mira study

PURPOSE

The aim of this study was to prospectively compare the therapy response and safety of microwave (MWA) and radiofrequency ablation (RFA) for the treatment of liver metastases using a dual ablation system.

METHODS

Fifty patients with liver metastases (23 men, mean age: 62.8 ± 11.8 years) were randomly assigned to MWA or RFA for thermal ablation using a one generator dual ablation system. Magnetic resonance imaging (MRI) was acquired before treatment and 24 h post ablation. The morphologic responses to treatment regarding size, volume, necrotic areas, and diffusion characteristics were evaluated by MRI. Imaging follow-up was obtained for one year in three months intervals, whereas clinical follow-up was obtained for two years in all patients.

RESULTS

Twenty-six patients received MWA and 24 patients received RFA (mean diameter: 1.6 cm, MWA: 1.7 cm, RFA: 1.5 cm). The mean volume 24 h after ablation was 37.0 cm3 (MWA: 50.5 cm3, RFA: 22.9 cm3, P < 0.01). The local recurrence rate was 0% (0/26) in the MWA-group and 8.3% (2/24) in the RFA-group (P = 0.09). The rate of newly developed malignant formations was 38.0% (19/50) for both groups (MWA: 38.4%, RFA: 37.5%, P = 0.07). The overall survival rate was 70.0% (35/50) after two years (MWA: 76.9%, RFA: 62.5%, P = 0.60). No major complications were reported.

CONCLUSION

In conclusion, MWA and RFA are both safe and effective methods for the treatment of liver metastases with MWA generating greater volumes of ablation. No significant differences were found for overall survival, rate of neoplasm, or major complications between both groups.

Laparoscopic Surgery for a Patient With Multiple Liver Metastases of Unknown Origin Concomitant With Gallbladder Tumor

BACKGROUND

The liver is the digestive organ where metastatic adenocarcinoma of unknown primary site is most often observed.

CASE REPORT

A 74-year-old man was diagnosed with a growing gallbladder tumor and multiple liver tumors limited to the left lateral sector. Liver tumors were suggested to be primary or secondary adenocarcinoma with no relation to the gallbladder tumor. Also for diagnostic purposes, laparoscopic full-thickness resection of the gallbladder, laparoscopic lateral sectionectomy and lymph node sampling were performed. The final histopathological diagnosis was hyperplastic polyp of the gallbladder and metastatic poorly differentiated adenocarcinoma of the liver. Liver tumors were suspected to originate from the stomach, duodenum, or small intestine; however, the primary sites could not be identified. The patient has been closely followed up without any chemotherapy 3 months after surgery.

CONCLUSION

Laparoscopic surgery can be strongly recommended for patients with multiple liver tumors of unknown origin concomitant with a gallbladder tumor.

Metachronous hepatic resection for liver only pancreatic metastases

BACKGROUND

The value of liver resection (LR) for metachronous pancreatic ductal adenocarcinoma (PDAC) metastases remains controversial. However, in light of increasing safety of liver resections, surgery might be a valuable option for metastasized PDAC in selected patients.

METHODS

We performed a retrospective, multicenter study including patients undergoing hepatectomy for metachronous PDAC liver metastases between 2004 and 2015 to analyze postoperative outcome and overall survival. All patients were operated with curative intent. Patients with oligometastatic metachronous liver metastasis with definitive chemotherapy (n = 8) served as controls.

RESULTS

Overall 25 patients in seven centers were included in this study. The median age at the time of LR was 63.8 years (56.9-69.9) and the median number of metastases in the liver was 1 (IQR 1-2). There were eight non-anatomical resections (32%), 15 anatomical minor (60%) and 2 major LR (8%). Postoperative complications occurred in eleven patients (eight Clavien-Dindo grade I complications (32%) and three grade IIIa complications (12%), respectively). The 30-day mortality was 0%. The median length of stay was 8.6 days (IQR 5-11). Median overall survival following LR was 36.8 months compared to 9.2 months in patients with metachronous liver metastasis with chemotherapy (p = 0007).

DISCUSSION

Liver resection for metachronous PDAC metastasis is safe and feasible in selected patients. To address general applicability and to find factors for patient selection, larger trials are urgently warranted.

Surgical Models to Explore Acellular Liver Scaffold Transplantation: Step-by-Step

Acellular liver scaffolds (ALS) have arisen as potential candidates for transplantation. Until now, all reports involving ALS transplantation failed in surgical method descriptions and do not offer support to scientists to reproduce the procedures used in experimental microsurgery to make the results comparable to literature. To overcome the lack of detail information, we described surgical steps details to perform heterotopic and partial orthotopic surgical models to promote ALS transplantation. After preservation and vessel cannulation steps, the liver grafts were decellularized. In addition, ex vivo blood perfusion tests were performed to obtain a successful anticoagulation treatment prior in vivo transplantation. Then, methods of partial liver resection, combination of hand-suture and cuff techniques to complete end-to-end anastomosis between the scaffold and the recipient animal were performed. These procedures which take 30-60 min and were efficient to allow acellular liver scaffold viability and recellularization of different types of cell post-surgery. In conclusion, our methods are practical and simple promising approach that provides the opportunity to investigate ways to achieve sufficient liver function post-transplantation in vivo.