An MRI Deep Learning Model Predicts Outcome in Rectal Cancer.

Background Deep learning (DL) models can potentially improve prognostication of rectal cancer but have not been systematically assessed. Purpose To develop and validate an MRI DL model for predicting survival in patients with rectal cancer based on segmented tumor volumes from pretreatment T2-weighted MRI scans. Materials and Methods DL models were trained and validated on retrospectively collected MRI scans of patients with rectal cancer diagnosed between August 2003 and April 2021 at two centers. Patients were excluded from the study if there were concurrent malignant neoplasms, prior anticancer treatment, incomplete course of neoadjuvant therapy, or no radical surgery performed. The Harrell C-index was used to determine the best model, which was applied to internal and external test sets. Patients were stratified into high- and low-risk groups based on a fixed cutoff calculated in the training set. A multimodal model was also assessed, which used DL model-computed risk score and pretreatment carcinoembryonic antigen level as input. Results The training set included 507 patients (median age, 56 years [IQR, 46-64 years]; 355 men). In the validation set (n = 218; median age, 55 years [IQR, 47-63 years]; 144 men), the best algorithm reached a C-index of 0.82 for overall survival. The best model reached hazard ratios of 3.0 (95% CI: 1.0, 9.0) in the high-risk group in the internal test set (n = 112; median age, 60 years [IQR, 52-70 years]; 76 men) and 2.3 (95% CI: 1.0, 5.4) in the external test set (n = 58; median age, 57 years [IQR, 50-67 years]; 38 men). The multimodal model further improved the performance, with a C-index of 0.86 and 0.67 for the validation and external test set, respectively. Conclusion A DL model based on preoperative MRI was able to predict survival of patients with rectal cancer. The model could be used as a preoperative risk stratification tool. Published under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Langs in this issue.

Survival after combined resection and ablation is not inferior to that after resection alone, in patients with four or more colorectal liver metastases.

PURPOSE: Colorectal liver metastases (CRLM) are the predominant factor limiting survival in patients with colorectal cancer. Multimodal treatment strategies are frequently necessary to achieve total tumor elimination. This study examines the efficacy of liver resection combined with local ablative therapy in comparison to liver resection only, in the treatment of patients with ≥ 4 CRLM. METHODS: This retrospective cohort study was conducted at the University Hospital RWTH Aachen, Germany. Patients with ≥ 4 CRLM in preoperative imaging, who underwent curative resection between 2010-2021, were included. Recurrent resections and deaths in the early postoperative phase were excluded. Ablation modalities included radiofrequency or microwave ablation, and irreversible electroporation. Differences in overall- (OS) and recurrence-free-survival (RFS) between patients undergoing combined resection-ablation vs. resection only, were examined. RESULTS: Of 178 included patients, 46 (27%) underwent combined resection-ablation and 132 (73%) resection only. Apart from increased rates of adjuvant chemotherapy in the first group (44% vs. 25%, p = 0.014), there were no differences in perioperative systemic therapy. Kaplan-Meier and log-rank test analyses showed no statistically significant differences in median OS (36 months for both, p = 0.638) or RFS (9 months for combined resection-ablation vs. 8 months, p = 0.921). Cox regression analysis showed a hazard ratio of 0.891 (p = 0.642) for OS and 0.981 (p = 0.924) for RFS, for patients undergoing resection only. CONCLUSION: For patients with ≥ 4 CRLM, combined resection-ablation is a viable option in terms of OS and RFS. Therefore, combined resection-ablation should be considered for complete tumor clearance, in patients with multifocal disease.

Value of prognostic scoring systems in the era of multimodal therapy for recurrent colorectal liver metastases.

BACKGROUND: Various predictive scoring systems have been developed to estimate outcomes of patients undergoing surgery for colorectal liver metastases (CRLM). However, data regarding their effectiveness in recurrent CRLM (recCRLM) are very limited. METHODS: Patients who underwent repeat hepatectomy for recCRLM at the University Hospital RWTH Aachen, Germany from 2010 to 2021 were included. Nine predictive scoring systems (Fong's, Nordlinger, Nagashima, RAS mutation, Tumor Burden, GAME, CERR, and Glasgow Prognostic score, Basingstoke Index) were evaluated by likelihood ratio (LR) χ2, linear trend (LT) χ2 and Akaike Information Criterion (AIC) for their predictive value regarding overall survival (OS) and recurrence free survival (RFS). RESULTS: Among 150 patients, median RFS was 9 (2-124) months with a 5-year RFS rate of 10%. Median OS was 39 (4-131) months with a 5-year OS rate of 32%. For RFS and OS, the Nagashima score showed the best prognostic ability (LT χ2 3.00, LR χ2 9.39, AIC 266.66 and LT χ2 2.91, LR χ2 20.91, 290.36). DISCUSSION: The Nagashima score showed the best prognostic stratification to predict recurrence as well as survival, and therefore might be considered when evaluating patients with recCRLM for repeat hepatectomy.

The role of re-resection in recurrent hepatocellular carcinoma.

PURPOSE: While liver resection is a well-established treatment for primary HCC, surgical treatment for recurrent HCC (rHCC) remains the topic of an ongoing debate. Thus, we investigated perioperative and long-term outcome in patients undergoing re-resection for rHCC in comparative analysis to patients with primary HCC treated by resection. METHODS: A monocentric cohort of 212 patients undergoing curative-intent liver resection for HCC between 2010 and 2020 in a large German hepatobiliary center were eligible for analysis. Patients with primary HCC (n = 189) were compared to individuals with rHCC (n = 23) regarding perioperative results by statistical group comparisons and oncological outcome using Kaplan-Meier analysis. RESULTS: Comparative analysis showed no statistical difference between the resection and re-resection group in terms of age (p = 0.204), gender (p = 0.180), ASA category (p = 0.346) as well as main preoperative tumor characteristics, liver function parameters, operative variables, and postoperative complications (p = 0.851). The perioperative morbidity (Clavien-Dindo ≥ 3a) and mortality were 21.7% (5/23) and 8.7% (2/23) in rHCC, while 25.4% (48/189) and 5.8% (11/189) in primary HCC, respectively (p = 0.851). The median overall survival (OS) and recurrence-free survival (RFS) in the resection group were 40 months and 26 months, while median OS and RFS were 41 months and 29 months in the re-resection group, respectively (p = 0.933; p = 0.607; log rank). CONCLUSION: Re-resection is technically feasible and safe in patients with rHCC. Further, comparative analysis displayed similar oncological outcome in patients with primary and rHCC treated by liver resection. Re-resection should therefore be considered in European patients diagnosed with rHCC.

Clinical value and limitations of the preoperative C-reactive-protein-to-albumin ratio in predicting post-operative morbidity and mortality after deceased-donor liver transplantation: a retrospective single-centre study.

Liver transplantation is still associated with a high risk of severe complications and post-operative mortality. This study examines the predictive value of the preoperative C-reactive-protein-to-albumin ratio (CAR) regarding perioperative morbidity and mortality in deceased-donor liver transplantation (DDLT) recipients. In total, 390 DDLT recipients between 05/2010 and 03/2020 were eligible. Predictive abilities of CAR were examined through receiver operating characteristic curve (ROC) analyses. Groups were compared using parametric and non-parametric tests as appropriate. Independent risk factors for morbidity and mortality were identified using uni- and multivariable logistic regression analyses. A good predictive ability for CAR was shown regarding perioperative morbidity (comprehensive complication index ≥75, Clavien-Dindo score ≥4a) and 12-month mortality, with an ideal cut-off of CAR = 26%. Patients with CAR>26% had significantly higher median CCI scores (60 vs. 43, P < 0.001), longer intensive care unit (ICU, 5 vs. 4 days, P < 0.001) and hospital (28 vs. 21 days, P < 0.001) stays and higher 12-month mortality rates (20% vs 6%, P < 0.001). Multivariable analyses identified CAR>26%, pre-OLT inpatient hospitalization (including ICU) and post-operative red blood cell transfusions as independent predictors of severe cumulative morbidity (CCI≥75). Preoperative CAR might be a reliable additional tool to predict perioperative morbidity and mortality in DDLT recipients.

Insufficient future liver remnant and preoperative cholangitis predict perioperative outcome in perihilar cholangiocarcinoma.

BACKGROUND: Major liver resection has evolved as the mainstay of treatment for patients with perihilar cholangiocarcinoma (pCCA). Here we assessed the suitability of preoperative future liver remnant (FLR) measurement to predict perioperative complications, since surgical morbidity and mortality are high compared to other malignancies. METHODS: Between 2011 and 2016, 91 patients with pCCA underwent surgery in curative intent at our institution. The associations of surgical complications with FLR and clinico-pathological characteristics were assessed using logistic regression analyses. Different methods of FLR assessment, the calculated-FLR (cFLR; ratio of FLR to total liver volume), standardized FLR (sFLR; ratio of FLR to liver volume estimated by body surface area) and FLR to bodyweight ratio (FLR/BW) were tested for validity. RESULTS: Multivariable analysis identified preoperative cholangitis (Exp(B) = 0.236; p = 0.030) as the single significant predictor of postoperative mortality and cFLR (Exp(B) = 0.009, p = 0.004) as the single significant predictor of major postoperative morbidity (Clavien-Dindo ≥ 3b). Based on these findings we designed a futility criterion (cFLR<40% OR preoperative cholangitis) predicting in-house mortality. CONCLUSIONS: In patients with pCCA, the preoperative FLR<40% as well as preoperative cholangitis are two risk factors to independently predict perioperative morbidity and mortality. The cFLR should be the preferred method of liver volumetry.

Prognostic factors of disease-free and overall survival in patients with hepatocellular carcinoma undergoing partial hepatectomy in curative intent.

PURPOSE: Tumor recurrence after liver resection continues to pose a major problem in hepatocellular carcinoma (HCC). Here we aimed to evaluate prognostic markers for disease-free (DFS) and overall survival (OS) in HCC-patients who underwent liver resection in curative intent. Additionally, we investigated the effects of HCC-recurrence in a subgroup of patients. METHODS: Between 2010 and 2016, 111 patients underwent surgical resection for HCC at our institution. A subgroup of 50 patients showed tumor recurrence (n = 50) during follow-up. The associations of DFS and OS with histopathologic characteristics were assessed using univariable and multivariable Cox regression analyses. RESULTS: Median DFS was 31 months and median OS was 27 months. Milan criteria (p = 0.045), macrovascular invasion (p = 0.044) and UICC tumor stage (p = 0.003) were independently associated with DFS while macrovascular invasion (p = 0.001) and MELD score (p = 0.010) were independently associated with OS. Tumor recurrence did not show an association with OS (p = 0.228). However, patients with HCC-recurrence who underwent repeat-surgical or interventional treatment showed improved OS compared to patients treated with palliative or sorafenib treatment alone (OS 18 months vs. 2 months; p < 0.001). CONCLUSION: Tumor recurrence alone is not associated with poor oncological outcome and repeat liver resections as well as local-ablative procedures may help to improve OS in HCC.

Cosmesis and Body Image in Patients Undergoing Single-port Versus Conventional Laparoscopic Cholecystectomy: A Multicenter Double-blinded Randomized Controlled Trial (SPOCC-trial).

OBJECTIVE: To evaluate cosmesis, body image, pain, and quality of life (QoL) after single-port laparoscopic cholecystectomy (SPLC) versus conventional 4-port laparoscopic cholecystectomy (4PLC). BACKGROUND: The impact of SPLC on improving cosmesis, body image, pain, and QoL has not been evaluated in double-blinded randomized controlled trials (RCT). This approach therefore remains controversial. METHODS: Between October 2011 and February 2014, 110 patients from 2 centers were randomly assigned to SPLC (n = 55) or 4PLC (n = 55). Primary endpoints were a validated cosmesis (3-24 points) and body image (5-20 points) score after 3 and 12 months. Secondary endpoints included operative duration, postoperative pain, complications, QoL, and length of hospital stay. Patients, physicians, and nurses were blinded until the seventh postoperative day. RESULTS: Demographics were equally distributed between both groups (mean age: 46 years, SD: 14, 62 females, 34 males). The SPLC-group showed superior mean cosmesis and body image compared with the 4PLC-group at 12-weeks (21 vs 16, P < 0.001 and 5 vs 6, P = 0.013, respectively) and at 1-year (24 vs 16, P < 0.001 and 5 vs 6, P < 0.017, respectively). Operation duration was longer in the SPLC-group (mean 101 vs 90 minutes, p = 0.031). Although postoperative pain was less in the SPLC-group (mean VAS 1 vs 2, p = 0.005), there were no differences in complications, and length of hospital-stay. CONCLUSIONS: This is the first multicenter double-blinded RCT reporting superior short- and long-term cosmetic and body image, postoperative pain, and QoL in SPLC compared with 4PLC. Although cost-effectiveness is still a subject of ongoing debate, SPLC should be offered to patients undergoing surgery for benign gallbladder disease.

Preoperative three-dimensional lung volumetry predicts respiratory complications in patients undergoing major liver resection for colorectal metastases.

Colorectal liver metastases (CRLM) are the predominant factor limiting survival in patients with colorectal cancer and liver resection with complete tumor removal is the best treatment option for these patients. This study examines the predictive ability of three-dimensional lung volumetry (3DLV) based on preoperative computerized tomography (CT), to predict postoperative pulmonary complications in patients undergoing major liver resection for CRLM. Patients undergoing major curative liver resection for CRLM between 2010 and 2021 with a preoperative CT scan of the thorax within 6 weeks of surgery, were included. Total lung volume (TLV) was calculated using volumetry software 3D-Slicer version 4.11.20210226 including Chest Imaging Platform extension ( http://www.slicer.org ). The area under the curve (AUC) of a receiver-operating characteristic analysis was used to define a cut-off value of TLV, for predicting the occurrence of postoperative respiratory complications. Differences between patients with TLV below and above the cut-off were examined with Chi-square or Fisher's exact test and Mann-Whitney U tests and logistic regression was used to determine independent risk factors for the development of respiratory complications. A total of 123 patients were included, of which 35 (29%) developed respiratory complications. A predictive ability of TLV regarding respiratory complications was shown (AUC 0.62, p = 0.036) and a cut-off value of 4500 cm3 was defined. Patients with TLV < 4500 cm3 were shown to suffer from significantly higher rates of respiratory complications (44% vs. 21%, p = 0.007) compared to the rest. Logistic regression analysis identified TLV < 4500 cm3 as an independent predictor for the occurrence of respiratory complications (odds ratio 3.777, 95% confidence intervals 1.488-9.588, p = 0.005). Preoperative 3DLV is a viable technique for prediction of postoperative pulmonary complications in patients undergoing major liver resection for CRLM. More studies in larger cohorts are necessary to further evaluate this technique.

Partial liver resection alters the bile salt-FGF19 axis in patients with perihilar cholangiocarcinoma: Implications for liver regeneration.

BACKGROUND: Extended liver resection is the only treatment option for perihilar cholangiocarcinoma (pCCA). Bile salts and the gut hormone FGF19, both promoters of liver regeneration (LR), have not been investigated in patients undergoing resection for pCCA. We aimed to evaluate the bile salt-FGF19 axis perioperatively in pCCA and study its effects on LR. METHODS: Plasma bile salts, FGF19, and C4 (bile salt synthesis marker) were assessed in patients with pCCA and controls (colorectal liver metastases), before and after resection on postoperative days (PODs) 1, 3, and 7. Hepatic bile salts were determined in intraoperative liver biopsies. RESULTS: Partial liver resection in pCCA elicited a sharp decline in bile salt and FGF19 plasma levels on POD 1 and remained low thereafter, unlike in controls, where bile salts rose gradually. Preoperatively, suppressed C4 in pCCA normalized postoperatively to levels similar to those in the controls. The remnant liver volume and postoperative bilirubin levels were negatively associated with postoperative C4 levels. Furthermore, patients who developed postoperative liver failure had nearly undetectable C4 levels on POD 7. Hepatic bile salts strongly predicted hyperbilirubinemia on POD 7 in both groups. Finally, postoperative bile salt levels on day 7 were an independent predictor of LR. CONCLUSIONS: Partial liver resection alters the bile salt-FGF19 axis, but its derailment is unrelated to LR in pCCA. Postoperative monitoring of circulating bile salts and their production may be useful for monitoring LR.

Improving the standard of lymph node retrieval after gastric cancer surgery.

AIMS: To examine factors that influence lymph node count and to study the relationship between nodal size and metastatic involvement in gastric cancer. METHODS AND RESULTS: Observational study comparing lymph node retrieval by manual nodal dissection (MND) and systematic fat blocking (SFB) from 114 gastrectomy specimens. The influence of lymph node retrieval method, patient characteristics, oncological factors and surgical approach on lymph node count were examined using regression models. The risk-adjusted cumulative sum chart method was also used to analyse lymph node count. The lymph node count increased during the course of this study (P < 0.005). Both pathologist and lymph node retrieval method were independent predictors for lymph node count. MND yielded lower lymph node counts than SFB (58 versus 66, P < 0.05). The pathologist influenced lymph node retrieval by MND (R(2) : 0.297-0.518, P < 0.0001), but not SFB (R(2) : 0.340-0.344, P > 0.05). The percentage of positive lymph nodes below 5 mm was 24.2% and 44.1% for MND and SFB, respectively, resulting in cancer upstaging (P = 0.037). CONCLUSIONS: Systematic fat blocking is associated with a higher total and positive lymph node yield compared to MND and is independent of the pathologist. Ignoring small lymph nodes can be a major cause for missing positive nodes, leading in turn to cancer down-staging.

The impact of the COVID-19 outbreak on emergency general surgery in the first German "hotspot region" Aachen-Heinsberg-A multicentre retrospective cohort study.

This study aimed to observe the impact of the COVID-19 outbreak on acute general surgery in the first German "hotspot" regions of Heinsberg and Aachen, during the first months of the pandemic. The incidence and severity of acute appendicitis, acute cholecystitis and mechanical bowel obstruction, were compared between March and May 2020 and a control period (same months of the previous three years). Pre-, intra- and postoperative data was compared between three regional hospitals of Heinsberg and the closest maximum care, university hospital. A total of 592 operated patients were included, 141 belonging to the pandemic cohort and 451 to the historic cohort. The pandemic group showed higher rates of clinical peritonitis (38% vs. 27%, p = 0.015), higher rates of mean white blood cell count (13.2±4.4 /nl vs. 12.3±4.7 /nl, p = 0.044) and mean C-reactive protein (60.3±81.1 mg/l vs. 44.4±72.6 mg/l, p = 0.015) preoperatively. Specifically in patients with acute appendicitis, there were less patients with catarrhal appendicitis (23% vs. 35%, p = 0.021) and a tendency towards more advanced histological findings in the pandemic cohort. In the university hospital, a 42% reduction in acute operated cases was observed at the onset of the pandemic (n = 30 in 2020 vs. n = 52 in 2019), whereas in the peripheral hospitals of Heinsberg there was only a 10% reduction (n = 111 in 2020 vs. n = 123 in 2019). The onset of the COVID-19 pandemic in our region was accompanied by advanced preoperative and intraoperative findings in patients undergoing emergency general surgery. A greater reduction in acute operated surgical cases was observed at the university hospital, in contrast to the smaller hospitals of Heinsberg, suggesting a possible shift of emergency patients, requiring immediate operation, from maximum care hospital to the periphery.

Novel machine learning algorithm can identify patients at risk of poor overall survival following curative resection for colorectal liver metastases.

BACKGROUND/PURPOSE: The primary cause of mortality in colorectal cancer is metastatic disease. We investigated the ability of a machine learning (ML) algorithm to stratify overall survival (OS) of patients undergoing curative resection for colorectal liver metastases (CRLM). METHODS: Patients undergoing curative liver resection for CRLM between 2010-2021 at the University Hospital RWTH Aachen were eligible for this retrospective study. Patients with recurrent metastases, incomplete resections, or early deaths, were excluded. A gradient-boosted decision tree (GBDT) model identified patients at risk of poor OS, based on clinicopathological characteristics. Differences in survival were compared with Kaplan-Meier analysis and the log-rank test. RESULTS: A total of 487 patients were split into training (n = 389, 80%) and test cohorts (n = 98, 20%). Of the latter, 20 (20%) were identified by the GBDT model as high-risk and showed significantly reduced OS (23 months vs 52 months, P = .005) and increased hazard ratio (2.434, 95%CI 1.280-4.627, P = .007). The strongest predictors were preoperative serum carcinoembryonic antigen (CEA), age, diameter of the largest metastasis, number of metastases, body mass index, and primary tumor grading. CONCLUSION: A GBDT model can identify high-risk patients regarding OS after curative resection of CRLM. Closer follow-up and aggressive systemic treatment strategies may be beneficial to these patients.

Calcification of the visceral aorta and celiac trunk is associated with renal and allograft outcomes after deceased donor liver transplantation.

PURPOSE: Atherosclerosis affects clinical outcomes in the setting of major surgery. Here we aimed to investigate the prognostic role of visceral aortic (VAC), extended visceral aortic (VAC+), and celiac artery calcification (CAC) in the assessment of short- and long-term outcomes following deceased donor orthotopic liver transplantation (OLT) in a western European cohort. METHODS: We retrospectively analyzed the data of 281 consecutive recipients who underwent OLT at a German university medical center (05/2010-03/2020). The parameters VAC, VAC+, or CAC were evaluated by preoperative computed tomography-based calcium quantification according to the Agatston score. RESULTS: Significant VAC or CAC were associated with impaired postoperative renal function (p = 0.0016; p = 0.0211). Patients with VAC suffered more frequently from early allograft dysfunction (EAD) (38 vs 26%, p = 0.031), while CAC was associated with higher estimated procedural costs (p = 0.049). In the multivariate logistic regression analysis, VAC was identified as an independent predictor of EAD (2.387 OR, 1.290-4.418 CI, p = 0.006). Concerning long-term graft and patient survival, no significant difference was found, even though patients with calcification showed a tendency towards lower 5-year survival compared to those without (VAC: 65 vs 73%, p = 0.217; CAC: 52 vs 72%, p = 0.105). VAC+ failed to provide an additional prognostic value compared to VAC. CONCLUSION: This is the first clinical report to show the prognostic role of VAC/CAC in the setting of deceased donor OLT with a particular value in the perioperative phase. Further studies are warranted to validate these findings. CT computed tomography, OLT orthotopic liver transplantation.

Successful Transplantation of a Liver from a Donor with HELLP Syndrome Undergoing Hypothermic Oxygenated Machine Perfusion (HOPE) Prior to Implantation.

BACKGROUND Liver transplantation (LT) has become the treatment of choice for patients with end-stage liver disease (ESLD). The organ shortage forced clinicians to use livers from donors with certain risk factors, so-called extended-criteria donor (ECD) organs. Hypothermic oxygenated machine perfusion (HOPE) is an alternative to conventional static cold storage and reduces early allograft injury in ECD organs. In this article we present the case of a 45-year-old man with hepatitis B virus (HBV)-associated cirrhosis and hepatocellular carcinoma (HCC) who underwent successful liver transplantation supported by pretransplant hypothermic oxygenated machine perfusion (HOPE) from a 34-year-old extended-criteria donor (ECD) with hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome. CASE REPORT Liver transplantation was scheduled for a 45-year-old man with hepatocellular carcinoma (HCC) due to hepatitis B virus-induced liver cirrhosis. The organ donor was a 34-year-old woman who had developed intracerebral hemorrhage and brain death due to HELLP syndrome after delivery. Compared to the day of admission to the intensive care unit, a decrease in the donor's transaminases was observed prior to organ procurement. Before transplantation, HOPE was conducted after regular back-table preparation of the graft. LT was performed according to the standard surgical techniques and a standardized immunosuppressive regimen was conducted. In the post-transplant period, transaminases peaked directly after the operation and normalized after 1 week. No major surgical complications occurred. The patient was discharged after a 24-day hospital stay with normal liver function. CONCLUSIONS This case report supports the benefits of using HOPE in ECD organs and it should be considered in livers of donors with HELLP syndrome to improve post-transplant outcome.

Optical coherence tomography and convolutional neural networks can differentiate colorectal liver metastases from liver parenchyma ex vivo.

PURPOSE: Optical coherence tomography (OCT) is an imaging technology based on low-coherence interferometry, which provides non-invasive, high-resolution cross-sectional images of biological tissues. A potential clinical application is the intraoperative examination of resection margins, as a real-time adjunct to histological examination. In this ex vivo study, we investigated the ability of OCT to differentiate colorectal liver metastases (CRLM) from healthy liver parenchyma, when combined with convolutional neural networks (CNN). METHODS: Between June and August 2020, consecutive adult patients undergoing elective liver resections for CRLM were included in this study. Fresh resection specimens were scanned ex vivo, before fixation in formalin, using a table-top OCT device at 1310 nm wavelength. Scanned areas were marked and histologically examined. A pre-trained CNN (Xception) was used to match OCT scans to their corresponding histological diagnoses. To validate the results, a stratified k-fold cross-validation (CV) was carried out. RESULTS: A total of 26 scans (containing approx. 26,500 images in total) were obtained from 15 patients. Of these, 13 were of normal liver parenchyma and 13 of CRLM. The CNN distinguished CRLM from healthy liver parenchyma with an F1-score of 0.93 (0.03), and a sensitivity and specificity of 0.94 (0.04) and 0.93 (0.04), respectively. CONCLUSION: Optical coherence tomography combined with CNN can distinguish between healthy liver and CRLM with great accuracy ex vivo. Further studies are needed to improve upon these results and develop in vivo diagnostic technologies, such as intraoperative scanning of resection margins.

Optical coherence tomography combined with convolutional neural networks can differentiate between intrahepatic cholangiocarcinoma and liver parenchyma ex vivo.

PURPOSE: Surgical resection with complete tumor excision (R0) provides the best chance of long-term survival for patients with intrahepatic cholangiocarcinoma (iCCA). A non-invasive imaging technology, which could provide quick intraoperative assessment of resection margins, as an adjunct to histological examination, is optical coherence tomography (OCT). In this study, we investigated the ability of OCT combined with convolutional neural networks (CNN), to differentiate iCCA from normal liver parenchyma ex vivo. METHODS: Consecutive adult patients undergoing elective liver resections for iCCA between June 2020 and April 2021 (n = 11) were included in this study. Areas of interest from resection specimens were scanned ex vivo, before formalin fixation, using a table-top OCT device at 1310 nm wavelength. Scanned areas were marked and histologically examined, providing a diagnosis for each scan. An Xception CNN was trained, validated, and tested in matching OCT scans to their corresponding histological diagnoses, through a 5 × 5 stratified cross-validation process. RESULTS: Twenty-four three-dimensional scans (corresponding to approx. 85,603 individual) from ten patients were included in the analysis. In 5 × 5 cross-validation, the model achieved a mean F1-score, sensitivity, and specificity of 0.94, 0.94, and 0.93, respectively. CONCLUSION: Optical coherence tomography combined with CNN can differentiate iCCA from liver parenchyma ex vivo. Further studies are necessary to expand on these results and lead to innovative in vivo OCT applications, such as intraoperative or endoscopic scanning.

The feasibility, safety and outcomes of laparoscopic re-operation for achalasia.

INTRODUCTION: Heller myotomy for achalasia is associated with a recurrence rate of around 10%, thus reoperative surgery is often necessitated. This paper aims to review the available literature on laparoscopic reoperation for achalasia in order to assess its feasibility and effectiveness. MATERIAL & METHODS: A Medline, Embase, Ovid, Cochrane database and Google(TM) Scholar search was performed with the following Mesh terms: "laparoscopic", "redo", "reoperative", "Heller's", "esophagomyotomy" and "achalasia". Outcomes of interest included patient demographics and details of primary procedure, operative details, intra- and post operative complications and symptom scores. RESULTS: Seven studies reported outcomes from 54 cases. Conversion occurred in 7% (4/54) of cases. Thirteen percent (7/54) of patients sustained intra-operative gastric or oesophageal perforation; however these were all noted and repaired intra-operatively leading to no subsequent morbidity. No deaths were reported. Pre- and post operative symptom scores were heterogeneous, however did appear to improve after the procedure. DISCUSSION: This review demonstrates that laparoscopic reoperation for achalasia is feasible and safe with complication rates comparable to the primary laparoscopic operation. It is recommended that laparoscopic reoperative Heller's myotomy should only be performed by surgeons with special interest in oesophagogastric surgery and adequate experience in laparoscopic surgery for achalasia.

Blunt pulmonary contusion: admission computed tomography scan predicts mechanical ventilation.

BACKGROUND: Blunt pulmonary contusion (BPC) evolves over 12 to 24 hours, and the initial plain radiographs fail to reliably identify patients at risk of clinical deterioration. Admission computed tomography (CT) may offer accurate characterization of BPC and early prediction of the need for mechanical ventilation (MV). METHODS: This was a combination of a 5-year retrospective study (January 2002 to April 2007) and a 6-month prospective study (September 2007 to February 2008) of adult blunt trauma (BT) patients with thoracic injuries and a chest CT upon hospital arrival. The primary outcome was MV due to thoracic trauma. To ensure that MV was required for BPC and not for associated injuries, all patients with significant extrathoracic injuries (Abbreviated Injury Scale score >2) were excluded. The extent of BPC was measured by two scoring systems. RESULTS: Of 392 patients (67% males; age, 48 years ± 21 years; Abbreviated Injury Scale score chest, 3 ± 1; and Injury Severity Score [ISS], 13 ± 6), 243 (62%) had BPC. Twenty-five (6%) patients required MV and two (0.5%) died. The combination of Glasgow Coma Scale (GCS) score <14, BPC score >2, and >4 ribs fractured predicted MV in 100% of the cases, and the absence of all factors precluded MV in 100%. In the prospective period of 6 months, 55 patients had BPC and we confirmed our finding that the absence of the three factors precludes MV. CONCLUSION: A simple score derived by the initial chest CT, in combination with GCS and the number of fractured ribs, can predict the need for MV early. In the presence of these predictors, patients should be admitted to a high level of monitoring.

MRI-Based Quantitation of Hepatic Steatosis Does Not Predict Hypertrophy Rate after Portal Vein Embolization in Patients with Colorectal Liver Metastasis and Normal to Moderately Elevated Fat Fraction.

The aim of this study was to correlate the pre-procedural magnetic-resonance-imaging-based hepatic fat fraction (hFF) with the degree of hypertrophy after portal vein embolization (PVE) in patients with colorectal cancer liver metastases (CRCLM). Between 2011 November and 2020 February, 68 patients with CRCLM underwent magnetic resonance imaging (MRI; 1.5 Tesla) of the liver before PVE. Using T1w chemical shift imaging (DUAL FFE), the patients were categorized as having a normal (<5%) or an elevated (>5%) hFF. The correlation of hFF, age, gender, initial tumor mass, history of chemotherapy, degree of liver hypertrophy, and kinetic growth rate after PVE was investigated using multiple regression analysis and Spearman's test. A normal hFF was found in 43/68 patients (63%), whereas 25/68 (37%) patients had an elevated hFF. The mean hypertrophy and kinetic growth rates in patients with normal vs. elevated hFF were 24 ± 31% vs. 28 ± 36% and 9 ± 9 % vs. 8 ± 10% (p > 0.05), respectively. Spearman's test showed no correlation between hFF and the degree of hypertrophy (R = -0.04). Multivariable analysis showed no correlation between hFF, history of chemotherapy, age, baseline tumor burden, or laterality of primary colorectal cancer, and only a poor inverse correlation between age and kinetic growth rate after PVE. An elevated hFF in a pre-procedural MRI does not correlate with the hypertrophy rate after PVE and should therefore not be used as a contraindication to the procedure in patients with CRCLM.