P-L16 The Impact of Covid-19 on the Management of Primary and Metastatic Liver Cancers; A Single Centre Experience

Background The Covid-19 pandemic has impacted on all aspects of health care. Surgical specialties have been affected by the impact on theatre time and space, staff re-deployments, reduced ICU capacity for non-Covid patients, and in some cases this has had a significant impact on wait time for surgery and overall surgical capacity. In our tertiary referral HPB unit, the service has been relocated to two different sites throughout the pandemic. We aimed to assess the impact of this on patients undergoing liver resection Methods We examined patient data for all patients undergoing liver resection in the 15 month period prior to the introduction of national lockdown, and compared this with all patients who have undergone liver resection since. We looked at total number of cases, ICU admission rates (planned vs unplanned), length of stay, case mix, histology, rates of laparoscopic vs open surgery, and length of time from completing neoadjuvant chemotherapy to surgery. Data were obtained from electronic care records and patient notes. Results The overall number of cases was similar (84 pre-covid vs 86 since) and basic patient demographics were unaffected. Median length of stay was the same for both groups (7 days). Colorectal metastases were the underlying pathology in the majority of cases (56/84 pre Covid, 56/86 post). Numbers of laparoscopic and laparoscopic converted to open cases were reduced in the post-Covid era, 12 prior versus four since. The median time from completion of neo-adjuvant chemotherapy to surgery was also affected, increasing from 46 to 62 days. Conclusions These data show some differences in patient care in the pre and post-Covid eras, in particular a lower rate of laparoscopic surgery and longer period of time between neo-adjuvant treatment and surgery. Longer follow up is required to see if these trends persist and their effect on long term survival and recurrence rates. However, despite the strains on the system there were similar numbers of patients pre and post Covid, indicating that patients are still presenting and being treated. This showed that staff responded well to the pressures of Covid, and trainee experience would have been similar

O-L04 Peri-operative thrombophilia in patients undergoing liver resection for colorectal metastases

Background The risk of major haemorrhage during liver surgery has decreased considerably in the modern era. However, there remains reluctance amongst liver surgeons to give routine peri-operative chemical thromboprophylaxis, either because of the perceived risk of bleeding, or transient post-operative abnormalities in conventional coagulation studies. The aim of this study was to ask whether a defined, homogeneous population of patients undergoing liver resection for colorectal metastases (CRM) were at risk from venous thromboembolism (VTE) prior to surgery, and what the impact of liver resection was on that risk. Methods A single-centre prospective observational cohort study comparing pre-, peri- and post-operative haemostasis variables in patients undergoing liver resection for CRM. Patients with cirrhosis, history of VTE or anticoagulated were excluded, as were patients undergoing small wedge, or laparoscopic liver resections. Blood samples for coagulation assays were collected pre-operatively, peri-operatively (after transection) and first post-operative day (13–20 hours post-operatively). Pre- and post-operative Tissue Factor messenger ribonucleic acid (TFmRNA) activation was measured from peripheral blood mononuclear cells (PBMCs) using semi-quantitative polymerase chain reaction (PCR). Patients received peri-operative mechanical thromboprophylaxis until mobile, plus chemical thromboprophylaxis on the first post-operative day, after venesection. Results Of 336 hepatectomies performed October 2017-December 2019, 60 resections in 57 patients were recruited. This included 46.7% major resections, with median (interquartile range [IQR]) blood loss 150.0mls (76.3-263.7), no blood transfusions, post-operative VTE events or deaths. Patients were prothrombotic pre-operatively (high factor VIIIC and thrombin generation velocity index), an effect exacerbated post-hepatectomy. Major hepatectomies had a significantly greater drop in Protein C, rise in Factor VIIIC and von Willebrand Factor, versus minor resections (p = 0.001,0.005,0.001 respectively). Patients with transection times greater than median (40minutes), had significantly increased median (IQR) PMBC-TFmRNA expression [1.65 (0.93-2.70)2ddCt], versus quicker transections [0.99 (0.69-1.28)2ddCt, p = 0.020]. Conclusions These data show the risk of major haemorrhage in elective liver resection in a high volume unit is low and administration of chemical thromboprophylaxis within 13-20 hours of surgery is safe and effective. The study demonstrates that patients with CRM are prothrombotic pre-operatively. Furthermore, this thrombophilia is exacerbated by liver resection, and most marked in patients with longer, more complex operations. These data suggest that chemical thromboprophylaxis should be considered earlier in the patient pathway, and has resulted in a change in practice for the authors.

P-L15 Fluorescence guided laparoscopic resection of Colorectal Liver Metastases: Same day administration of indocyanine green with use of SPY- Colour Segmented Fluorescence imaging to identify tumours intra-operatively

Background Near-infrared fluorescent (NIRF) imaging using indocyanine green (ICG) has various applications in minimally invasive surgery. There are a number of techniques in timing and dose administration. Visually different fluorescent enhancement patterns correlate with different pathologies to aid identification of lesions intra-operatively. The aim of this study is to present our experience with utilisation of Colour Segmented Fluorescence ICG mode in laparoscopic liver surgery for colorectal liver metastases. Methods We present a single surgeon (SA) experience with the use of laparoscopic fluorescence guided imaging surgery (L-FGIS). Between November 2020 and July 20201, L-FGIS was used in seven patients with suspected CRLM. ICG was administered intravenously at a dose of 0.2 to 0.3 mg/kg IV 2-3 hours prior to liver surgery. Through use of the SPY Colour Segmented Fluorescence (CSF) imaging mode, the image is scaled as to NIRF fluorescence intensity to allow for the clear identification of the CRLM intra-operatively. Results A total of seven patients (Four males) with median age of 74.3 years (range: 30.5 -86) underwent L-FGIS during the study period. Two out of seven patients underwent re-do liver surgery. The median size of the tumour was 27mm (range: 10-65mm) and median number of tumours were one (range: 1-2). To visualise the tumour and to avoid interference of green background liver, ICG camera was switched to CSF mode. All lesions had signet ring appearance under CSF mode (see figure 1). Except in one patient (necrotic lesion), the histology of resected specimen contained a well to moderately differentiated colorectal adenocarcinoma metastasis. R0 resection was achieved in all patients and median clearance of the tumour was 3mm (range 0.4-10mm). Conclusions In our limited experience ICG administered at least 2-3 hours prior to surgery can identify superficially located colorectal metastases, provided ICG camera is switched to CSF mode. Superficially located lesions are easily identifiable under CSF mode. CSF mode helped us to identify the lesions and to mark the resection margin. The use of ICG is an important advancement in CRLM surgery and further research is needed to optimise image interpretation and correlate with clinical resection outcomes.

EP.FRI.121 Unusual sites of colorectal cancer metastases – A complete systematic review

Background While colorectal cancer (CRC) usually metastasizes to liver, lungs and central nervous system, spread to more unusual sites is rarely reported in literature. We aimed to investigate unusual colorectal metastases (UCRM), their clinical course and disease progression. Methods MEDLINE, EMBASE and Cochrane Library were searched by independent reviewers to identify clinical studies to date that reported UCRM and relevant demographic/clinical data were extracted. Results We identified 349 patients, involving 28 sites (bone, musculo-skeletal, skin, brain/spinal cord, head, eye, oral mucosa, thyroid, mediastinum, heart, bronchus, breast, biliary/GI tract, stomach, pancreas, spleen, adrenal, urinary tract, inguinal canal, ovaries, vagina, vulva, testes, spermatic cord, prostate, penis) with male preponderance and median age of 59 years (IQR=54.5-65). These were diagnosed at a median interval of 18 months (IQR=6-36)) after a median follow-up of 12 months (IQR=6-22.5). More were metachronous (n = 210) with recurrence rate of 15.75%. Primary CRC staging revealed T3 in 61% (28%-T4), equal distribution of N0/N1 (38%/37%) and M0 in 85%. 74% of primaries were surgically resected (96%=adenocarcinomas) and 54% underwent adjuvant therapy. UCRM were resected in 45% of cases and showed same histology as primary. 30% had chemotherapy. Only 8% were palliated. Overall morality was 35.24%. Conclusion This is the first comprehensive review looking at clinical course and outcomes of patients with UCRM. Most of these developed in patients with primary T3/N0 staging. Outlook of these patients is comparable to those with usual metastatic disease. Judicious and rigorous surveillance is the key to early detection and timely management.

Serum Matrix Metalloproteinase-8 and Myeloperoxidase Predict Survival after Resection of Colorectal Liver Metastases

<b><i>Introduction:</i></b> Matrix metalloproteinases (MMPs) have been extensively studied in several malignancies, and myeloperoxidase (MPO) is a promising new prognostic biomarker. We investigated the prognostic value of MMP-8, MMP-9, and MPO, as well as carcinoembryonic antigen (CEA), CA19-9, and C-reactive protein (CRP) in colorectal cancer with operable liver metastases. <b><i>Methods:</i></b> This study included 419 patients who underwent liver resection for colorectal metastases at the Helsinki University Hospital between 2000 and 2013. Serum samples were drawn before and 3 months after liver resection. We evaluated associations of MMP-8, MMP-9, MPO, CRP, CEA, and CA19-9 concentrations to disease-free survival (DFS) and overall survival (OS) using the Cox proportional hazards model and Kaplan-Meier log-rank method. <b><i>Results:</i></b> In univariate Cox regression analyses, pre- and postoperatively high MMP-8 (HR 1.53, 95% CI: 1.07–2.19, <i>p</i> = 0.021 and HR 1.45, 95% CI: 1.01–2.09, <i>p</i> = 0.044, respectively) associated with worse 10-year OS. Postoperatively high MPO indicated better 5-year DFS (HR 0.70, 95% CI: 0.54–0.90, <i>p</i> = 0.007). Elevated pre- and postoperative CEA and CA19-9 as well as postoperative CRP indicated impaired survival. <b><i>Conclusions:</i></b> Pre- and postoperatively high MMP-8 associates with worse 10-year OS, and postoperatively high MPO associates with better 5-year DFS. CEA, CA19-9, and CRP are also prognostic.