Alternative forms of portal vein revascularization in liver transplant recipients with complex portal vein thrombosis.

BACKGROUND & AIMS: Complex portal vein thrombosis (PVT) is a challenge in liver transplantation (LT). Extra-anatomical approaches to portal revascularization, including renoportal (RPA), left gastric vein (LGA), pericholedochal vein (PCA), and cavoportal (CPA) anastomoses, have been described in case reports and series. The RP4LT Collaborative was created to record cases of alternative portal revascularization performed for complex PVT. METHODS: An international, observational web registry was launched in 2020. Cases of complex PVT undergoing first LT performed with RPA, LGA, PCA, or CPA were recorded and updated through 12/2021. RESULTS: A total of 140 cases were available for analysis: 74 RPA, 18 LGA, 20 PCA, and 28 CPA. Transplants were primarily performed with whole livers (98%) in recipients with median (IQR) age 58 (49-63) years, model for end-stage liver disease score 17 (14-24), and cold ischemia 431 (360-505) minutes. Post-operatively, 49% of recipients developed acute kidney injury, 16% diuretic-responsive ascites, 9% refractory ascites (29% with CPA, p <0.001), and 10% variceal hemorrhage (25% with CPA, p = 0.002). After a median follow-up of 22 (4-67) months, patient and graft 1-/3-/5-year survival rates were 71/67/61% and 69/63/57%, respectively. On multivariate Cox proportional hazards analysis, the only factor significantly and independently associated with all-cause graft loss was non-physiological portal vein reconstruction in which all graft portal inflow arose from recipient systemic circulation (hazard ratio 6.639, 95% CI 2.159-20.422, p = 0.001). CONCLUSIONS: Alternative forms of portal vein anastomosis achieving physiological portal inflow (i.e., at least some recipient splanchnic blood flow reaching transplant graft) offer acceptable post-transplant results in LT candidates with complex PVT. On the contrary, non-physiological portal vein anastomoses fail to resolve portal hypertension and should not be performed. IMPACT AND IMPLICATIONS: Complex portal vein thrombosis (PVT) is a challenge in liver transplantation. Results of this international, multicenter analysis may be used to guide clinical decisions in transplant candidates with complex PVT. Extra-anatomical portal vein anastomoses that allow for at least some recipient splanchnic blood flow to the transplant allograft offer acceptable results. On the other hand, anastomoses that deliver only systemic blood flow to the allograft fail to resolve portal hypertension and should not be performed.

The self-regulation for learning online (SRL-O) questionnaire.

The Self-Regulation for Learning Online (SRL-O) questionnaire was developed to encompass the breadth of motivational beliefs and learning strategies that are often used in online and/or blended learning contexts. No current measure meets all these needs. This study used two non-duplicate samples to provide evidence of the psychometric properties of SRL-O using exploratory factor analyses (sample 1, n = 313), and confirmatory factor analyses, convergent and content validity and reliability (sample 2, n = 321). The SRL-O has a 10-factor structure, made up of (1) online self-efficacy, (2) online intrinsic motivation, (3) online extrinsic motivation, (4) online negative achievement emotion, (5) planning and time management, (6) metacognition, (7) study environment, (8) online effort regulation, (9) online social support, and (10) online task strategies. The SRL-O was also found to have two superordinate factors (motivational beliefs and learning strategies). The SRL-O was demonstrated to be a psychometrically sound measure of online SRL for learners studying in online and blended learning contexts. There is no other online self-regulated learning questionnaire that currently covers such a wide range of motivational beliefs and learning strategies.

Abdominal Organ Preservation Solutions in the Age of Machine Perfusion.

The past decade has been the foreground for a radical revolution in the field of preservation in abdominal organ transplantation. Perfusion has increasingly replaced static cold storage as the preferred and even gold standard preservation method for marginal-quality organs. Perfusion is dynamic and offers several advantages in comparison with static cold storage. These include the ability to provide a continuous supply of new metabolic substrates, clear metabolic waste products, and perform some degree of organ viability assessment before actual transplantation in the recipient. At the same time, the ongoing importance of static cold storage cannot be overlooked, in particular when it comes to logistical and technical convenience and cost, not to mention the fact that it continues to work well for the majority of transplant allografts. The present review article provides an overview of the fundamental concepts of organ preservation, providing a brief history of static cold preservation and description of the principles behind and basic components of cold preservation solutions. An evaluation of current evidence supporting the use of different preservation solutions in abdominal organ transplantation is provided. As well, the range of solutions used for machine perfusion of abdominal organs is described, as are variations in their compositions related to changing metabolic needs paralleling the raising of the temperature of the perfusate from hypothermic to normothermic range. Finally, appraisal of new preservation solutions that are on the horizon is provided.

Liver resection and ablation for squamous cell carcinoma liver metastases.

BACKGROUND: Limited evidence exists to guide the management of patients with liver metastases from squamous cell carcinoma (SCC). The aim of this retrospective multicentre cohort study was to describe patterns of disease recurrence after liver resection/ablation for SCC liver metastases and factors associated with recurrence-free survival (RFS) and overall survival (OS). METHOD: Members of the European-African Hepato-Pancreato-Biliary Association were invited to include all consecutive patients undergoing liver resection/ablation for SCC liver metastases between 2002 and 2019. Patient, tumour and perioperative characteristics were analysed with regard to RFS and OS. RESULTS: Among the 102 patients included from 24 European centres, 56 patients had anal cancer, and 46 patients had SCC from other origin. RFS in patients with anal cancer and non-anal cancer was 16 and 9 months, respectively (P = 0.134). A positive resection margin significantly influenced RFS for both anal cancer and non-anal cancer liver metastases (hazard ratio 6.82, 95 per cent c.i. 2.40 to 19.35, for the entire cohort). Median survival duration and 5-year OS rate among patients with anal cancer and non-anal cancer were 50 months and 45 per cent and 21 months and 25 per cent, respectively. For the entire cohort, only non-radical resection was associated with worse overall survival (hazard ratio 3.21, 95 per cent c.i. 1.24 to 8.30). CONCLUSION: Liver resection/ablation of liver metastases from SCC can result in long-term survival. Survival was superior in treated patients with liver metastases from anal versus non-anal cancer. A negative resection margin is paramount for acceptable outcome.

How to Handle Arterial Conduits in Liver Transplantation? Evidence From the First Multicenter Risk Analysis.

OBJECTIVE: The aims of the present study were to identify independent risk factors for conduit occlusion, compare outcomes of different AC placement sites, and investigate whether postoperative platelet antiaggregation is protective. BACKGROUND: Arterial conduits (AC) in liver transplantation (LT) offer an effective rescue option when regular arterial graft revascularization is not feasible. However, the role of the conduit placement site and postoperative antiaggregation is insufficiently answered in the literature. STUDY DESIGN: This is an international, multicenter cohort study of adult deceased donor LT requiring AC. The study included 14 LT centers and covered the period from January 2007 to December 2016. Primary endpoint was arterial occlusion/patency. Secondary endpoints included intra- and perioperative outcomes and graft and patient survival. RESULTS: The cohort was composed of 565 LT. Infrarenal aortic placement was performed in 77% of ACs whereas supraceliac placement in 20%. Early occlusion (≤30 days) occurred in 8% of cases. Primary patency was equivalent for supraceliac, infrarenal, and iliac conduits. Multivariate analysis identified donor age >40 years, coronary artery bypass, and no aspirin after LT as independent risk factors for early occlusion. Postoperative antiaggregation regimen differed among centers and was given in 49% of cases. Graft survival was significantly superior for patients receiving aggregation inhibitors after LT. CONCLUSION: When AC is required for rescue graft revascularization, the conduit placement site seems to be negligible and should follow the surgeon's preference. In this high-risk group, the study supports the concept of postoperative antiaggregation in LT requiring AC.

Exploring the Presence of Core Skills for Surgical Practice Through Simulation.

OBJECTIVE: The ability to simulate procedures in silico has transformed surgical training and practice. Today's simulators, designed for the training of a highly specialized set of procedures, also present a powerful scientific tool for understanding the neural control processes that underpin the learning and application of surgical skills. Here, we examined whether 2 simulators designed for training in 2 different surgical domains could be used to examine the extent to which fundamental sensorimotor skills transcend surgical specialty. DESIGN, SETTING & PARTICIPANTS: We used a high-fidelity virtual reality dental simulator and a laparoscopic box simulator to record the performance of 3 different groups. The groups comprised dentists, laparoscopic surgeons, and psychologists (each group n = 19). RESULTS: The results revealed a specialization of performance, with laparoscopic surgeons showing the highest performance on the laparoscopic box simulator, while dentists demonstrated the highest skill levels on the virtual reality dental simulator. Importantly, we also found that a transfer learning effect, with laparoscopic surgeons and dentists showing superior performance to the psychologists on both tasks. CONCLUSIONS: There are core sensorimotor skills that cut across surgical specialty. We propose that the identification of such fundamental skills could lead to improved training provision prior to specialization.

Hepatopancreatoduodenectomy -a controversial treatment for bile duct and gallbladder cancer from a European perspective.

BACKGROUND: Hepatopancreatoduodenectomy (HPD) is an aggressive operation for treatment of advanced bile duct and gallbladder cancer associated with high perioperative morbidity and mortality, and uncertain oncological benefit in terms of survival. Few reports on HPD from Western centers exist. The purpose of this study was to evaluate safety and efficacy for HPD in European centers. METHOD: Members of the European-African HepatoPancreatoBiliary Association were invited to report all consecutive patients operated with HPD for bile duct or gallbladder cancer between January 2003 and January 2018. The patient and tumor characteristics, perioperative and survival outcomes were analyzed. RESULTS: In total, 66 patients from 19 European centers were included in the analysis. 90-day mortality rate was 17% and 13% for bile duct and gallbladder cancer respectively. All factors predictive of perioperative mortality were patient and disease-specific. The three-year overall survival excluding 90-day mortality was 80% for bile duct and 30% for gallbladder cancer (P = 0.013). In multivariable analysis R0-resection had a significant impact on overall survival. CONCLUSION: HPD, although being associated with substantial perioperative mortality, can offer a survival benefit in patient subgroups with bile duct cancer and gallbladder cancer. To achieve negative resection margins is paramount for an improved survival outcome.

Current role of trisectionectomy for hepatopancreatobiliary malignancies.

BACKGROUND: Trisectionectomy is a treatment option in extensive liver malignancy, including colorectal liver metastases (CRLM). However, the reported experience of this procedure is limited. Therefore, we present our experience with right hepatic trisectionectomy (RHT) for CRLM as an example and discuss the changing role of trisectionectomy in the context of modern treatment alternatives based on a literature review. METHODS: Between January 1993 and December 2014 all patients undergoing RHT at a single center in the UK for CRLM were included. Patient and tumor characteristics were reviewed and a multivariate analysis was done. Based on a literature review the role of trisectionectomy in the treatment of HPB malignancies was discussed. RESULTS: A total of 211 patients undergoing RHT were included. Overall perioperative morbidity was 40.3%. Overall 90-day mortality was 7.6% but reduced to 2.8% over time. Multivariate analysis identified additional organ resection (P = .040) and blood transfusion (P = .028) as independent risk factors for morbidity. Multiple tumors, total hepatic vascular exclusion, and R1 resection were independent risk factors for significantly decreased disease-free and disease-specific survival. Further surgery for recurrence after RHT significantly prolonged survival compared with palliative chemotherapy only. CONCLUSION: With the further development of surgical and multimodal treatment strategies in CRLM the indications for trisectionectomy are decreasing. Having being formerly associated with high rates of perioperative morbidity and mortality, this single-center experience clearly shows that these concomitant risks decrease with experience, liberal use of portal vein embolization and improved patient selection. Trisectionectomy remains relevant in selected patients.

Ablation or Resection for Colorectal Liver Metastases? A Systematic Review of the Literature.

Background: Successful use of ablation for small hepatocellular carcinomas (HCC) has led to interest in the role of ablation for colorectal liver metastases (CRLM). However, there remains a lack of clarity about the use of ablation for colorectal liver metastases (CRLM), specifically its efficacy compared with hepatic resection. Methods: A systematic review of the literature on ablation or resection of colorectal liver metastases was performed using MEDLINE, Cochrane Library, and Embase until December 2018. The aim of this study was to summarize the evidence for ablation vs. resection in the treatment of CRLM. Results: This review identified 1,773 studies of which 18 were eligible for inclusion. In the majority of the studies, overall survival (OS) and disease-free survival (DFS) were significantly higher and local recurrence (LR) rates were significantly lower in the resection groups. On subgroup analysis of solitary CRLM, resection was associated with improved OS, DFS, and reduced LR. Three series assessed the outcome of resection vs. ablation for technically resectable CRLM, and showed improved outcome in the resection group. In fact, there were no studies showing a survival advantage of ablation compared to resection in the treatment of CRLM. Conclusions: Resection remains the "gold standard" in the treatment of CRLM and should not be replaced by ablation at present. This review supports the use of ablation only as an adjunct to resection and as a single treatment option when resection is not safely possible.

Variation in the Use of Resection for Colorectal Cancer Liver Metastases.

OBJECTIVE: The aim of this study was to investigate variation in the frequency of resections for colorectal cancer liver metastases across the English NHS. BACKGROUND: Previous research has shown significant variation in access to liver resection surgery across the English NHS. This study uses more recent data to identify whether inequalities in access to liver resection still persist. METHODS: All adults who underwent a major resection for colorectal cancer in an NHS hospital between 2005 and 2012 were identified in the COloRECTal cancer data Repository (CORECT-R). All episodes of care, occurring within 3 years of the initial bowel operation, corresponding to liver resection were identified. RESULT: During the study period 157,383 patients were identified as undergoing major resection for a colorectal tumor, of whom 7423 (4.7%) underwent ≥1 liver resections. The resection rate increased from 4.1% in 2005, reaching a plateau around 5% by 2012. There was significant variation in the rate of liver resection across hospitals (2.1%-12.2%). Patients with synchronous metastases who have their primary colorectal resection in a hospital with an onsite specialist hepatobiliary team were more likely to receive a liver resection (odds ratio 1.22; 95% confidence interval, 1.10-1.35) than those treated in one without. This effect was absent in resection for metachronous metastases. CONCLUSIONS: This study presents the largest reported population-based analysis of liver resection rates in colorectal cancer patients. Significant variation has been observed in patient and hospital characteristics and the likelihood of patients receiving a liver resection, with the data showing that proximity to a liver resection service is as important a factor as deprivation.

Segment 2/3 Hypertrophy is Greater When Right Portal Vein Embolisation is Extended to Segment 4 in Patients with Colorectal Liver Metastases: A Retrospective Cohort Study.

BACKGROUND: In patients with colorectal cancer liver metastases (CRLM), right portal vein embolisation (RPVE) is used to increase the volume of the future remnant liver (FRL) before major hepatic resection. It is not established whether embolisation of segment 4 in addition RPVE (RPVE + 4) induces greater hypertrophy of the FRL. Limitations of prior studies include heterogenous populations and use of hypertrophy metrics sensitive to baseline variables. METHODS: From 2010 to 2015, consecutive patients undergoing RPVE or RPVE + 4 for CRLM, who had not undergone prior major hepatic resection and in whom imaging was available, were included in a retrospective study. Data were extracted from hospital electronic records. Volumetric assessments of segments 2-3 were made on cross-sectional imaging before and after embolisation and corrected for standardised liver volume. RESULTS: Ninety-nine patients underwent PVE, and 60 met the inclusion criteria. Thirty-eight patients underwent RPVE, and 22 underwent RPVE + 4. Forty-five patients had undergone median 6 cycles of prior chemotherapy. Eighteen patients had FRL metastases at PVE, and 16 had undergone subsegmental metastasectomy in the FRL. Assessments of the degree of hypertrophy (DH) of segments 2/3 were made at median 35 (interquartile range 30-49) days after PVE. RPVE + 4 resulted in a significantly greater increase in DH than RPVE (7.7 ± 1.8% vs 11.3 ± 2.6%, p = 0.011). No confounding association between baseline variables and the decision to undertake RPVE or RPVE + 4 was identified. Median survival was 2.4 years and was not influenced by segment 4 embolisation. CONCLUSION: RPVE + 4 results in greater DH of segments 2/3 than RPVE in people with CLRM.

Expectations of outcomes in patients with colorectal cancer.

BACKGROUND: Understanding patients' expectations of their treatment is critical to ensure appropriate treatment decisions, and to explore how expectations influence coping, quality of life and well-being. This study aimed to examine these issues related to treatment in patients with colorectal cancer. METHODS: A literature search from January 1946 to September 2016 was performed to identify available data regarding patients' expectations of outcomes following colorectal cancer treatment. A narrative synthesis of the evidence was planned. RESULTS: Of 4337 items initially identified, 20 articles were included in the review. In studies presenting data on overall and short-term survival, patients considerably overestimated prognosis. Patients also had unrealistic expectations of the negative aspects of chemotherapy and stomas. There was marked discordance between patients' and clinicians' expectations regarding chemotherapy, end-of-life care, bowel function and psychosocial outcomes. Level of education was the most consistent factor influencing the accuracy of patients' expectations. CONCLUSION: Patients with colorectal cancer frequently have unrealistic expectations of treatment. Marked disparities exist between patients' and clinicians' expectations of outcomes.

Impact of blood transfusion on outcomes following resection for colorectal liver metastases in the modern era.

BACKGROUND: Evidence suggests that perioperative blood loss and blood transfusions are associated with poorer long-term outcomes in patients undergoing other oncological surgery. The aim of this study was to determine the long-term outcomes of patients requiring a blood transfusion post-hepatectomy for colorectal liver metastases (CRLM). METHODS: This is a retrospective review from 2005 to 2012. Overall survival (OS) and recurrence-free survival (RFS) were assessed using Kaplan-Meier curves. Red blood cell transfusion (RBCT) and other clinic-pathological parameters were handled as covariates for Cox regression analysis. RESULTS: Six hundred and ninety patients were included. Median follow-up was 33 months. Sixty-four (9.3%) patients required a perioperative RBCT. RBCT was a predictor for decreased OS (median 41 versus 49 months, P = 0.04). However, on multivariate regression analyses preoperative chemotherapy, post-operative complications and Clinical Risk Score were independently associated with reduced OS, though RBCT was not. There was no association between RBCT and RFS (median 15 versus 17 months, P = 0.28). CONCLUSIONS: RBCT is not independently associated with a poorer OS.

The rate of false-positive diagnosis of colorectal liver metastases in patients undergoing resection with the development of a novel, externally validated risk score.

BACKGROUND: Diagnostic error in patients undergoing resection of colorectal liver metastases (CRLM) is unusual but exposes patients to unnecessary risks associated with treatment. The primary aim of this study was to determine the rate of and risk factors for a false-positive diagnosis of colorectal liver metastases in patients undergoing hepatic resection. The secondary aim was to develop and validate a risk score to predict a false-positive diagnosis. METHODS: Patients were identified from prospectively maintained databases. Patients who underwent a first liver resection for presumed colorectal liver metastases were divided into 2 groups: CRLMPOS (colorectal liver metastases present on histology or appearance of complete pathologic response to preoperative chemotherapy) and CRLMNEG (all others). Univariable analysis and multivariable binary logistic regression were used to identify risk factors for CRLMNEG. Risk scores were developed for CRLMNEG both with and without the use of preoperative carcinoembryonic antigen and were validated on an external cohort. RESULTS: 3.1% of patients in both test and validation cohorts were CRLMNEG (39/1,252 and 59/1,900, respectively). CRLMNEG patients had fewer (P = .006) and smaller lesions (P < .001) with lower serum levels of carcinoembryonic antigen (P < .001), T (P = .031) and N (P < .001) and a lower Dukes' stage of the primary (P < .001). The risk score performed well (area under the receiver operating characteristic curve 0.869; standard error = 0.030; P < .001) with reasonable performance on validation (area under receiver operating characteristic curve 0.743; standard error = 0.058; P < .001]). CONCLUSION: A false-positive diagnosis of colorectal liver metastases affected the same proportion of patients in 2 unrelated cohorts. This study identified risk factors for false-positive diagnosis with development of a novel risk score supported by external validation.

Operating list composition and surgical performance.

BACKGROUND: Recent reviews suggest that the way in which surgeons prepare for a procedure (warm up) can affect performance. Operating lists present a natural experiment to explore this phenomenon. The aim was to use a routinely collected large data set on surgical procedures to understand the relationship between case list order and operative performance. METHOD: Theatre lists involving the 35 procedures performed most frequently by senior surgeons across 38 private hospitals in the UK over 26 months were examined. A linear mixed-effects model and matched analysis were used to estimate the impact of list order and the cost of switching between procedures on a list while controlling for key prognosticators. The influence of procedure method (open versus minimally invasive) and complexity was also explored. RESULTS: The linear mixed-effects model included 255 757 procedures, and the matched analysis 48 632 pairs of procedures. Repeating the same procedure in a list resulted in an overall time saving of 0·98 per cent for each increase in list position. Switching between procedures increased the duration by an average of 6·48 per cent. The overall reduction in operating time from completing the second procedure straight after the first was 6·18 per cent. This pattern of results was consistent across procedure method and complexity. CONCLUSION: There is a robust relationship between operating list composition and surgical performance (indexed by duration of operation). An evidence-based approach to structuring a theatre list could reduce the total operating time.

Impact of a National Controlled Donation After Circulatory Death (DCD) Program on Organ Donation in the United Kingdom: A 10-Year Study.

Organ transplantation is the most successful treatment for some forms of organ failure, yet a lack of organs means many die on the waiting list. In the United Kingdom, the Organ Donation Taskforce was set up to identify barriers to organ donation and in 2008 released its first report (Organ Donation Taskforce Report; ODTR). This study assesses the success since the ODTR and examines the impact of the United Kingdom's controlled donation after circulatory death (DCD) program and the controversies surrounding it. There were 12 864 intended donation after brain death (DBD) or DCD donors from April 2004 to March 2014. When the 5 years preceding the ODTR was compared to the 5 years following, intended DCD donors increased 292% (1187 to 4652), and intended DBD donors increased 11% (3327 to 3698). Organs retrieved per intended DBD donor remained static (3.30 to 3.26), whereas there was a decrease in DCD (1.54 to 0.99) due to a large rise in donors who did not proceed to donation (325 to 2464). The majority of DCD donors who proceeded did so within 30 min from time of withdrawal. Our study suggests further work on converting eligible referrals to organ donation and exploring methods of converting DCD to DBD donors.

Radical operation for hilar cholangiocarcinoma in comparable Eastern and Western centers: Outcome analysis and prognostic factors.

BACKGROUND: Extensive resection for hilar cholangiocarcinoma is the most effective treatment, but high morbidity and poor prognosis remain concerns. Previous data have shown marked differences in outcomes between comparable Eastern and Western centers. We compared the outcomes of the management for hilar cholangiocarcinoma at one Japanese and one British institution with comparable experience. METHODS: Of 298 consecutive patients with hilar cholangiocarcinoma evaluated at Hirosaki University Hospital, Japan and St. James's University Hospital, Leeds, UK, 183 underwent radical resection. Clinicopathologic variables and postoperative outcomes were compared. RESULTS: Significant differences were not observed between the Hirosaki and Leeds cohorts in overall outcomes despite several differences in the patient characteristics. Although there was a difference in 90-day mortality (2.5% vs 13.6%, respectively), disease-specific 5-year survival rates were 32.8% and 31.9%, respectively (P = .767). Multivariate analysis identified trisectionectomy (odds ratio = 2.32; P = .010), combined pancreatoduodenectomy (odds ratio = 7.88; P = .010), and perioperative blood transfusion (odds ratio = 1.88; P = .045) were associated with postoperative major complications, while preoperative biliary drainage associated with postoperative major complications, while preoperative biliary drainage (risk ratio = 2.21; P = .018), perioperative blood transfusion (risk ratio = 1.58; P = .029), lymph node metastasis (risk ratio = 2.00; P = .002), moderate/poorly differentiated tumor (risk ratio = 1.72; P = .029), microvascular invasion (risk ratio = 1.63; P = .046), and R1 resection (risk ratio = 1.90; P = .005) were risk factors for poor survival. CONCLUSION: Disease-specific survival and prognostic factors were similar in both centers. Meticulous operative technique to avoid perioperative blood transfusion may improve long-term survival.

Upregulated WEE1 protects endothelial cells of colorectal cancer liver metastases.

Surgical resection of colorectal cancer liver metastases (CLM) can be curative, yet 80% of patients are unsuitable for this treatment. As angiogenesis is a determinant of CLM progression we isolated endothelial cells from CLM and sought a mechanism which is upregulated, essential for angiogenic properties of these cells and relevant to emerging therapeutic options. Matched CLM endothelial cells (CLMECs) and endothelial cells of normal adjacent liver (LiECs) were superficially similar but transcriptome sequencing revealed molecular differences, one of which was unexpected upregulation and functional significance of the checkpoint kinase WEE1. Western blotting confirmed that WEE1 protein was upregulated in CLMECs. Knockdown of WEE1 by targeted short interfering RNA or the WEE1 inhibitor AZD1775 suppressed proliferation and migration of CLMECs. Investigation of the underlying mechanism suggested induction of double-stranded DNA breaks due to nucleotide shortage which then led to caspase 3-dependent apoptosis. The implication for CLMEC tube formation was striking with AZD1775 inhibiting tube branch points by 83%. WEE1 inhibitors might therefore be a therapeutic option for CLM and could be considered more broadly as anti-angiogenic agents in cancer treatment.