{"entity":{"id":"idea-pu-extended-clot-prevention-after-surgery","kind":"idea","name":"Four weeks of blood-clot prevention after major abdominal or pelvic cancer surgery","aka":[],"tldr":"Blood clots after a major operation for bowel, gynaecological or other abdominal cancer often appear after discharge. Extending preventive blood thinners to four weeks roughly halved clots in pooled trials without more major bleeding, and professional societies recommend it, yet among 23,527 older Americans having bowel cancer surgery in 2016 and 2017, 4.7 per cent received it.","summary":"The evidence. A meta-analysis of seven randomised and prospective studies with 4,807 patients found that extending prophylaxis to two to six weeks after abdominal or pelvic cancer surgery reduced all venous thromboembolism from 5.6 to 2.6 per cent (relative risk 0.44, number needed to treat 39) and proximal deep vein thrombosis from 2.8 to 1.4 per cent, without a significant increase in major bleeding (1.8 against 1.0 per cent). Symptomatic pulmonary embolism and three-month mortality did not differ significantly, which is the honest limit: much of the reduction is in clots found by scanning. A larger 2021 meta-analysis of 68 studies with more than 1.6 million patients found clinical clots fell from 2.1 to 1.0 per cent with extended low-molecular-weight heparin, again without more clinically relevant bleeding.\n\nThe guidelines. Extended prophylaxis after cancer surgery is recommended by major professional societies, as the Medicare study below notes, and the 2023 ASCO guideline update added the tablets apixaban and rivaroxaban as options for it, with a weak recommendation. That matters for adherence, because tablets can replace four weeks of injections.\n\nThe measured gap. In SEER-Medicare data for 23,527 patients over 64 having colorectal cancer resection in 2016 and 2017, 4.7 per cent received extended prophylaxis within seven days of discharge; 10.2 per cent at NCI-designated centres and 1.7 per cent at non-teaching hospitals. The authors conclude that use \"remains limited even in large, specialized hospitals\". No source OnCo found measures this in the NHS.","asOf":"2026-10-20","links":[{"label":"Key et al., Venous thromboembolism prophylaxis and treatment in patients with cancer: ASCO guideline update (Journal of Clinical Oncology 2023)","url":"https://doi.org/10.1200/JCO.23.00294"},{"label":"Fagarasanu et al., Role of extended thromboprophylaxis after abdominal and pelvic surgery in cancer patients: a systematic review and meta-analysis (Annals of Surgical Oncology 2016)","url":"https://doi.org/10.1245/s10434-016-5127-1"},{"label":"Knoll et al., Extended thromboprophylaxis following major abdominal or pelvic cancer-related surgery: a systematic review and meta-analysis (Thrombosis Research 2021)","url":"https://doi.org/10.1016/j.thromres.2021.06.010"},{"label":"Donahue et al., Guideline-concordant extended pharmacologic venous thromboembolism prophylaxis utilization after colorectal cancer resection is low regardless of patient factors or hospital characteristics (Diseases of the Colon and Rectum 2025)","url":"https://doi.org/10.1097/dcr.0000000000003616"}],"tags":["protocol-upgrade","upgrade:proven-unevenly-used","evidence:moderate"],"related":["idea-pu-enhanced-recovery-with-measured-compliance"],"cancers":["colorectal","rectal-cancer","ovarian","endometrial","gastric","pancreatic","urothelial"],"sections":["surgery"],"technologies":["cancer-associated-thrombosis"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["vte"],"trials":[],"people":[],"bottlenecks":["b-knowledge-diffusion","b-care-fragmentation"],"keyPapers":["paper-key-j-clin-oncol"],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"A discharge prescribing default of four weeks of prophylaxis after major abdominal or pelvic cancer surgery, with an opt-out reason recorded, raises use above 80 per cent of eligible patients and reduces symptomatic venous thromboembolism at 90 days without increasing major bleeding.","rationale":"Pooled trials show the reduction, professional societies recommend it, oral options now exist, and national claims data show fewer than one in twenty eligible older patients receive it.","test":"A stepped-wedge implementation of a discharge default across surgical units, with prescribing, adherence, symptomatic venous thromboembolism and major bleeding at 90 days as endpoints from linked records.","maturity":"being-tested-at-scale","actor":"clinic","cost":"small","horizonYears":2},"route":"/ideas/idea-pu-extended-clot-prevention-after-surgery/","neighbours":{"idea":[{"id":"idea-pu-enhanced-recovery-with-measured-compliance","kind":"idea","name":"Enhanced recovery after cancer surgery, with each element's compliance measured and fed back","route":"/ideas/idea-pu-enhanced-recovery-with-measured-compliance/"}],"cancer":[{"id":"urothelial","kind":"cancer","name":"Bladder & urothelial cancer","route":"/cancers/urothelial/"},{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"endometrial","kind":"cancer","name":"Endometrial cancer","route":"/cancers/endometrial/"},{"id":"gastric","kind":"cancer","name":"Gastric & gastro-oesophageal junction cancer","route":"/cancers/gastric/"},{"id":"ovarian","kind":"cancer","name":"Ovarian cancer","route":"/cancers/ovarian/"},{"id":"pancreatic","kind":"cancer","name":"Pancreatic ductal adenocarcinoma","route":"/cancers/pancreatic/"},{"id":"rectal-cancer","kind":"cancer","name":"Rectal cancer","route":"/cancers/rectal-cancer/"}],"section":[{"id":"surgery","kind":"section","name":"Surgery & Interventional","route":"/fronts/surgery/"}],"technology":[{"id":"cancer-associated-thrombosis","kind":"technology","name":"Cancer-associated thrombosis prevention and treatment","route":"/technologies/cancer-associated-thrombosis/"}],"term":[{"id":"vte","kind":"term","name":"Venous thromboembolism (VTE)","route":"/terms/vte/"}],"bottleneck":[{"id":"b-care-fragmentation","kind":"bottleneck","name":"Fragmented care and guideline gaps","route":"/bottlenecks/b-care-fragmentation/"},{"id":"b-knowledge-diffusion","kind":"bottleneck","name":"Knowledge reaches practice too slowly","route":"/bottlenecks/b-knowledge-diffusion/"}],"paper":[{"id":"paper-key-j-clin-oncol","kind":"paper","name":"Venous Thromboembolism Prophylaxis and Treatment in Patients With Cancer: ASCO Guideline Update","route":"/key-papers/paper-key-j-clin-oncol/"}]}}