Thrombo – embolism (Blood clots) in cancer surgery - Are we doing enough to prevent it?

By Dr Narasimhaiah Srinivasaiah
Senior Consultant,
Apollo Institute of Colorectal Surgery - Bangalore

Venous thrombo-embolism also termed VTE is a significant healthcare issue in patients who undergo abdomino-pelvic surgery. It only gets worse, if the patient has been suffering from abdomino-pelvic cancers. The spectrum of VTE consists of clots in the legs (Deep venous thrombosis), pelvic venous thrombosis (PVT) and pulmonary embolism (PE), which is life threatening.

VTE associated with malignancy reduces survival. Pulmonary embolism is the second most common cause of death in patients with cancer. Post operatively, deep vein thrombosis (DVT) and pulmonary embolism (PE) are twice and thrice more common respectively, in cancer patients compared to the ones operated for benign causes. Post-operation DVT prevalence in colorectal surgery is estimated to be around 20%.

Surgery on cancer patients is a significant risk factor for thrombosis. This could be attributed to disruption of Virchow’s triad, with prolonged immobilisation etc. Although the rate of prevalence of pre-operative DVT is unknown, it certainly is a risk factor for pulmonary embolism post operatively. There is no doubt that a standardised thrombo-prophylaxis is vital in this group to prevent clots and their consequences.

Anecdotal evidence suggests that there is a lack of standardisation and uniformity in thrombo-prophylaxis practice worldwide. There are guidelines on thrombo-embolic prophylaxis in the west from The Association of Coloproctology of Great Britain and
Ireland (ACPGBI) and The National Institute for Health and Care Excellence (NICE). They suggest a combination of mechanical and chemo prophylaxis with graduated compression stockings and blood thinning drugs or injections. These should be used peri-operatively. A large evidence base has favoured post–operative thromboprophylaxis for many years, with wide international variation in the different approaches. There are recent NICE guidelines on venous thromboembolism prophylaxis. NICE guidelines recommend a combined thromboprophylaxis for gastro- intestinal surgical procedures with increased risk of venous hromboembolism and low risk of major bleeding. The mechanical venous thromboembolism prophylaxis should commence at admission, and continue until mobility is no longer significantly reduced.

The mechanical venous thromboembolism prophylaxis includes anti-embolism stockings (thigh or knee length), foot impulse devices, or intermittent pneumatic compression devices (thigh or knee length). For chemo-prophylaxis fondaparinux,
Low Molecular Weight Heparin (LMWH), or Unfractionated Heparin (for renal failure patients) is recommended to be continued until mobility is no longer significantly reduced (generally 5–7 days). There are now guidelines which recommend chemo-
prophylaxis for 4 weeks post-operatively in cancer patients undergoing major abdomino-pelvic surgery. The care we provide should lay emphasis on patient centred care. Patient compliance and resources are factors that need consideration.

In India, there is a rising incidence of abdomino-pelvic cancers. There is increase in the number of abdomino – pelvic procedures undertaken. In this context it is important that we consider peri-operative and post operative thrombo-prophylaxis to reduce both mortality and morbidity.