Thromboprohylaxis in orthopedic surgery and traumatology

Orthopaedic and trauma surgery are classified according 3 groups of venous thromboembolic risk. Elective total hip replacement (THR) or total knee replacement (TKR), hip fracture surgery or trauma patients are at high risk. Isolated lower extremity injury with fracture is at moderate risk whereas this risk is low without fracture as well as with knee arthroscopy. In THR and TKR, low molecular weight heparin (LMWH), fondaparinux or melagatran-ximelagatran are strongly recommended. The routine use of other anticoagulants, in particular vitamin K antagonist are not recommended. In patients at high risk of venous thromboembolism as for example trauma patients, optimal use of intermittent pneumatic compression is an alternative option in case of contra-indication to anticoagulant prophylaxis. Graduated compression stockings enhance the efficacy of pharmacological methods. In schedule surgery, initiation of prophylaxis with LMWH may be started postoperatively. To reduce the haemorrhagic risk of anticoagulants, timing of first postoperative dose is essential and is proper to each drug. Duration of prophylaxis depends on the surgical and the individual patients' risk. Extended prophylaxis in THR for up to 42 days with LMWH and up to 35 days with fondaparinux in hip fracture surgery is recommended. However extended prophylaxis after 14 days in TKR has not demonstrated a higher efficacy and should only be considered for patients with additional risk factors. In patients with isolated lower extremity injury or undergoing knee arthroscopy, LMWH should not be routinely used according to a low or a moderate risk and/or the duration of prophylaxis required. But LMWH has to be considered for patients with additional risk factors. Prophylaxis in other orthopedic procedures has not been assessed and will be extrapolated from the above recommendations.     

Low molecular weight heparin for the prevention of venous thromboembolism after abdominal surgery

BACKGROUND: Abdominal surgery carries a significant risk of venous thrombosis, a risk further increased in patients with cancer. METHODS: Embase and Pubmed searches between 1980 and 2003, using the key words 'heparin,' 'surgery,' 'abdominal or rectal or colorectal or rectum or colon' and 'clinical trial', were conducted to identify studies of thromboprophylaxis in patients having abdominal surgery. RESULTS: A total of 16 comparative studies were identified. These show that low molecular weight heparin (LMWH) is as effective as unfractionated heparin (UFH) in reducing venous thromboembolism after abdominal surgery and, at appropriate doses, can reduce bleeding complications. In very high-risk patients, a higher dose of LMWH may offer increased efficacy without increasing bleeding risk. Extending the standard 7-10-day period of prophylaxis may benefit certain high-risk groups; recent data show a significant benefit of 4-week enoxaparin thromboprophylaxis compared with a standard regimen, at no cost to safety. CONCLUSION: Patients undergoing abdominal surgery should be stratified according to thromboembolism risk and managed accordingly. LMWH is a recommended alternative to UFH in moderate- or high-risk patients. In patients with cancer, high doses of LMWH may offer increased efficacy without increasing the bleeding risk and an extended 4-week period of prophylaxis appears beneficial.     

Prevention of venous thromboembolism following cardiac, vascular or thoracic surgery

In the absence of thromboprophylaxis, coronary artery bypass graft surgery (CABG), intrathoracic surgery (thoracotomy or video-assisted thoracoscopy), abdominal aortic surgery and infrainguinal vascular surgery are high-risk surgeries for the development of venous thromboembolic events (VTE). The incidence of VTE following surgery of the intrathoracic aorta, carotid endarterectomy or mediastinoscopy is unknown. Data from the litterature are lacking to draw evidence-based recommandations for venous thromboprophylaxis after these three types of surgeries, and the following guidelines are but experts'opinions (Grade D recommendations). Thromboprophylaxis is recommended after CABG (Grade D), with either subcutaneous (SC) low molecular weight heparin (LMWH) or SC or intravenous (i.v.) unfractioned heparin (UH) (PTT target = 1.1-1.5 time control value) (both grade D). This may be combined with the use of intermittent pneumatic compression device (Grade B). After valve surgery. The anticoagulation recommended to prevent valve thrombosis is sufficient in order to prevent VTE. We recommend thromboprophylaxis with either LMWH or low dose UH to prevent VTE after aortic or lower limbs infrainguinal vascular surgery (both grade B and D). Vitamine K antagonists (VKA) are not recommended in this indication (Grade D). We recommend thromprophylaxis following intrathoracic surgery via thoracotomy or videoassisted thoracoscopy (grade C). Either subcutaneous LMWH or subcutaneous or i.v. low dose UH may be used (Grade C). Efficacy of intermittent pneumatic compression device has been demonstrated in a study (grade C). VKA are not recommended (grade D). No further recommendation regarding the duration of thromboprophylaxis after these three types of surgeries can be made.     

Perioperative deep vein thrombosis prevention: what works, what does not work and does it improve outcome?

PURPOSE OF REVIEW: To critically evaluate the benefit/risk ratio of some strategies for venous thromboembolism prophylaxis (VTE) RECENT FINDINGS: A growing body of evidence shows that graduated elastic stockings are not effective in medical patients. Special surgical settings as bariatric surgery deserve attention with a high VTE risk and no evidence-based data with regard to prophylaxis. Extended prophylaxis is being evaluated in these patients, whereas its efficacy has been demonstrated in abdominal and pelvic surgery for cancer. New oral anticoagulants are about to change the clinical landscape but yet some issues are not solved: no antidote, no monitoring, no standardization for the perioperative bridging in patients with therapeutic doses. In addition, they have not been tested in fragile patients in whom an increased bleeding risk could be feared. Finally, a large bunch of guidelines are now available to help the physician in the decision-making process. SUMMARY: Studies evaluating the benefit/risk ratio of graduated elastic stockings should now take place in surgery. Increasing and splitting the anticoagulant dose (mainly low molecular weight heparins) by two injections a day could be recommended in bariatric surgery and morbidly obese patients. New anticoagulant agents should also be tested in special populations, following the European Medicines Agency guidance. The methodology of clinical trials in VTE prophylaxis has to be moved forward, pending the choice of debatable surrogate end-points as asymptomatic venous thrombosis and disputed issues on the assessment of major bleeding.     

Perioperative thromboprophylaxis in children: development of a guideline for management

Background:  Venous thromboembolic (VTE) events can occur in children at the time of surgery where a patient has associated prothrombotic risk factors. There is currently little advice available to anesthetists on how to assess the risks and provide prophylaxis.
Aim/Objective:  To increase awareness of thrombosis in the perioperative pediatric patient, and to give some guidance when considering prophylaxis in this group.
Method/Results:  A guideline outlining risk factors for venous thromboembolism in patients presenting for surgery was written as a flowchart. Recommendations for low risk patients was early mobilization and good hydration; for moderate risk patients having major general surgery to include physical prophylaxis where size permits, i.e. elastic stockings and compression devices; for high-risk patients undergoing major orthopaedic or general surgery to also receive prophylactic low molecular weight heparin enoxaparin 0.5 mg·kg⁻¹ b.d.
Conclusion:  Children with multiple risk factors for VTE should be considered for prophylactic measures when presenting for prolonged major surgery.     

Prevention of deep-vein thrombosis after total hip and knee replacement. Low-molecular-weight heparin in combination with intermittent pneumatic compression

After total hip (THR) or knee replacement (TKR), there is still an appreciable risk of developing deep-vein thrombosis despite prophylaxis with low-molecular-weight heparin (LMWH). In a prospective, randomised study we examined the efficacy of LMWH in combination with intermittent pneumatic compression in patients undergoing primary unilateral THR or TKR. We administered 40 mg of enoxaparin daily to 131 patients combined with either the use of intermittent pneumatic compression or the wearing of graduated compression stockings. Compression ultrasonography showed no evidence of thrombosis after LMWH and intermittent pneumatic compression. In the group with LMWH and compression stockings the prevalence of thrombosis was 28.6% (40% after TKR, 14% after THR). This difference was significant (p < 0.0001). In the early post-operative phase after THR and TKR, combined prophylaxis with LMWH and intermittent pneumatic compression is more effective than LMWH used with graduated compression stockings.     

Deep vein thrombosis and malignancy: a surgical oncologist's perspective

Oncology patients are at increased risk of developing deep vein thrombosis (DVT) and its potentially fatal sequel, pulmonary embolism. This is due to multiple factors, including the presence of the malignancy itself, comorbid factors and therapy-related interventions. Issues that are peculiar to venous thrombosis in the oncology setting are discussed, based on a MEDLINE search of the English literature. These include the need to screen for malignancy in idiopathic DVT, a high index of suspicion for venous thrombosis in the cancer patient, the use of vena cava filters, and the anti-neoplastic effects of heparin. Asian patients appear to have a lower incidence of DVT compared to Caucasians. A recommended regimen for prophylaxis of DVT must take into account the varying thrombosis risk associated with different malignancies. Cancer patients not undergoing abdominal, pelvic or orthopaedic surgery (e.g. mastectomy) should use elastic compression stockings and be mobilized early, whereas low-molecular-weight heparin should be given to those undergoing more major surgery. In advanced malignancy, treatment of DVT palliates symptoms. These patients may need long-term anticoagulation with warfarin.     

Venous Thromboembolism in Cancer Patients Undergoing Major Surgery

Background  Cancer patients undergoing major abdominal or pelvic surgery are at considerable risk of venous thromboembolism (VTE). The genesis of thromboses in malignancy is complicated, and reflects the interaction and derangement of multiple molecular pathways. Furthermore, the nature and location of the cancer, as well as the type surgery involved, are thought to affect the level of VTE risk. These considerations may therefore affect treatment decisions. Methods  We performed multiple Medline searches with terms including but not limited to VTE, cancer, surgery, abdominal, colorectal, unfractionated heparin (UFH), and low-molecular-weight heparin (LMWH) to identify reviews, meta-analyses, nonrandomized and randomized controlled trials, and clinical guidelines relating to management of VTE in patients with abdominal cancer. Results  VTE incidence in patients with malignancy varied according to cancer type, location, stage of progression, and the use of catheters and/or chemotherapy. Thromboprophylaxis with UFH or LMWH reduces the risk of developing VTE in these patients. However, LMWHs have a favorable risk-benefit profile over UFH and extending the duration prophylaxis may improve outcomes. Conclusion  A number of recommendations can be made for the prevention of VTE in patients undergoing abdominal or pelvic surgery for cancer: (1) risk-stratify all patients according to defined evidence-based guidelines; (2) for most abdominal surgical oncology patients at risk, use of both an anticoagulant and mechanical means are indicated and beneficial; and (3) consider extended-duration prophylaxis (up to 28 days) in those patients with major abdominal/pelvic operations and impaired mobility, preferably with LMWH.     

Thrombo‐prophylaxis in colorectal surgery: a National Questionnaire Survey of the members of the Association of Coloproctology of Great Britain and Ireland

Aim Available guidelines from the National Institute for Health and Clinical Excellence (NICE) and the Association of Coloproctology of Great Britain and Ireland (ACPGBI) recommend combined (medical + mechanical) thrombo‐ prophylaxis. A Cochrane Library review recommends self‐administered low‐molecular‐weight heparin (LMWH) for 2–3 weeks following surgery. In the light of the recent guidelines from the ACPGBI and NICE, we undertook a National Questionnaire Survey to assess current thrombo‐prophylaxis practice among colorectal surgeons in the UK. Method A 10‐item questionnaire was designed to enquire into the current management strategy of postoperative thrombo‐prophylaxis. The postal questionnaire survey was sent to all 490 active consultant members of the ACPGBI. Results Of the 490 questionnaires sent, 259 (52.8%) were returned fully completed. Among these, all (100%) respondents reported the routine use of thrombo‐prophylaxis, with 243 (93.8%) following departmental guidelines. Combined medical and mechanical prophylaxis was used by 247 (95.40%) respondents. A small number – 12 (4.6%) – used medical prophylaxis only. LMWH was the preferred medical‐prophylactic agent of 243 (93.8%) repondents. The majority, 176 (68%), started thrombo‐prophylaxis on admission and stopped it at discharge. Seventy‐one (27.4%) respondents recommended thrombo‐prophylaxis after hospital discharge for an average duration of 4–6 weeks, preferring graduated compression stockings followed by LMWH. Conclusion The National Questionnaire Survey on thrombo‐prophylaxis demonstrated a high degree of concordance with the available guidelines, except for thrombo‐prophylaxis to be continued postoperatively for a period of 28 days/4 weeks.     

Prophylaxis of thromboembolic events during urologic surgery

Few scientific evidences are available in the literature, and the methodologic quality of the studies is often under average. Nevertheless, the conclusions are the following. Nephrectomy, renal transplantation, open surgery of the lower urinary tract and lumbar or pelvic lymph nodes dissection are at high risk for thromboembolic events. Other open or endoscopic urological procedures are at low risk. The laparoscopic approach doesn't change the risk associated with the procedure itself. Thromboprophylaxis is recommended in high-risk procedures. There was no evidence to recommend starting the prophylaxis before more than after the procedure. The use of low molecular weight heparin is recommended for prophylaxis. It can be associated with compressive stockings. It is recommended to treat for around seven days after the procedure. In case of cancer surgery, prophylaxis could be needed for four to six weeks.     

Postoperative venous thrombosis in general surgery patients and perioperative prophylaxis

In a population of general surgery patients in Western countries, there was a 19% incidence of deep vein thrombosis (DVT) and a 1.6% incidence of pulmonary embolism (PE), with 0.9% of patients experiencing fatal PE. In Japan, there was a 15.8% incidence of DVT and a 0.34% incidence of PE, with 0.08% of patients experiencing fatal PE in a population of abdominal surgery patients. The incidences of PE and fatal PE in our department were 0.11% and 0.03%, respectively. We started to use intermittent pneumatic compression (IPC) for the prophylaxis of postoperative PE in 1999 and then added elastic stockings in 2002 and low-dose unfractionated heparin (LDUH) in 2003 for prophylaxis. The incidence of PE has dropped and that of fatal PE has become 0% with the use of such prophylactic measures. When the risk of venous thromboembolism of the 15 patients who experienced PE in our department were assessed using the Japanese Guidelines for Prevention of Venous Thromboembolism, 13 patients were assessed as high risk and 2 as low risk. The mean age and mean body mass index of the 15 patients were 54 yeas old and 24.8, respectively, and PE was not limited to obese or elderly patients. Such findings appear to indicate the difficulty of risk assessment for PE. Therefore we started to use IPC, elastic stockings, and LDUH for the prophylaxis of PE and DVT for all general surgery patients from April 2004. These prophylactic measures are recommended for the highest-risk patients in the Japanese Guidelines for Prevention of Venous Thromboembolism. There have so far been no serious bleeding complications with the administration of LDUH. We will continue to observe the effects of prophylaxis and the risk of bleeding.     

Perioperative antithrombotic prophylaxis in varicose vein surgery

Antithrombotic regimens to prevent venous thromboembolism are standard in the treatment of in-and outpatients with thrombotic risk factors. A classification of the level of risk is made depending on the age, kind of operation, existing hereditary or acquired thrombophilic diatheses and concomitant disease. The antithrombotic prophylaxis is performed in accordance with the classification of risk level in low, moderate, high and highest risk levels. Varicose disease is a thrombotic risk factor. Varicose vein surgery may be classified as thrombogenic. Patients with varicose vein surgery and without other clinical risk factors are low-risk patients. In case of other acquired or hereditary risk factors antithrombotic prophylaxis in varicose vein surgery with low molecular weight heparin should be used. Compression elastic stockings are obligatory.     

Use of venous thromboembolism prophylaxis for surgical patients: a multicentre analysis of practice in Spain.

OBJECTIVE: To assess the use of venous thromboembolism prophylaxis in surgical patients. DESIGN: Retrospective multicentre study. SETTING: Eight acute-care teaching hospitals with more than 400 beds, Spain. PATIENTS: Medical records of all consecutive patients undergoing operations in the general surgical and trauma and orthopaedic services during the month of April, 1997, were randomly selected. INTERVENTION: The sample size for each type of operation (general, trauma-orthopaedic) was calculated from the number of operations done at each hospital (with an absolute precision of 5%, and an alpha error of 5%) and the prevalence of the use of venous thromboembolism prophylaxis obtained from a random sample of 50 records (25 from patients in general surgery and 25 from patients in orthopaedic surgery) from each centre. MAIN OUTCOME MEASURES: Appropriate and inappropriate pharmacological prophylaxis defined according to a combination of risk categories for venous thromboembolism, doses of antithrombotic agents given, time of starting prophylaxis, and its duration. RESULTS: A total of 1848 medical records (general surgery, n = 1025; trauma-orthopaedic surgery, n = 823) were included. Physical methods (elastic stockings, intermittent pneumatic compression) were used in only 0.3% of patients. Pharmacological prophylaxis consisted of low molecular weight heparin in 99% of cases. The percentage given heparin-based prophylaxis was 54%. Overall, appropriate prophylaxis was given in 1175 patients (64%). Use of thromboprophylaxis ranged from 27% to 70% among the participating hospitals. Prophylaxis was more likely to be appropriate in orthopaedic patients (577, 70%) than in general surgical patients (598, 58%) in both the high and moderate risk categories. CONCLUSIONS: Given the large variability between the participating hospitals, more specific protocols and recommendations about prophylaxis of thromboembolism in surgical patients are needed.     

Thromboembolic prophylaxis in head trauma and multiple-trauma patients

The association between trauma and venous thromboembolism (VTE) is well recognized. VTE consists mainly of deep venous thrombosis (DVT) and pulmonary embolism, a complication that leads to mortality in nearly 50% of cases. Without thromboprophylaxis, the risk of DVT exceeds 50%, but even with routine use of prophylaxis,one third of patients may develop DVT. Despite these findings, appropriate DVT prophylaxis is often not prescribed in trauma patients, mainly because of fear that VTE prophylaxis increases bleeding in injured tissues. Pharmacological VTE prophylaxis is based on the use of low-molecular weight heparins (LMWH). Once-daily or twice-daily LMWH protocols started within 36 h of trauma and continued throughout the hospital stay, or once-daily LMWH followed by a twice-daily protocol are possible options. Mechanical VTE prophylaxis by graduated compression stockings or intermittent pneumatic compression provides suboptimal protection, and its use is recommended only in combination with LMWH prophylaxis unless active bleeding is not controlled. The routine use of VTE prophylaxis in trauma patients is a standard of care. The use of LMWH, started once primary hemostasis has been accomplished, is safe, efficacious and cost-effective in the majority of trauma patients, including TBI patients.     

Thromboprophylaxis in elective spinal surgery and spinal cord injury

The risk of deep vein thrombosis (DVT) after spinal cord injury is very high. Without prophylaxis the incidence of DVT using venography is 81% and the risk of symptomatic DVT is between 12 and 23%. The risk is much lower in elective spine surgery. After discectomy or laminectomy on less than two spine levels, the risk of DVT is less than 1%. After spinal fusion or extended laminectomy, the risk can be estimated between 0.3 and 2.2%. A prophylaxis is recommended for all patients after spinal cord injury (grade A). The association of a mechanical method and heparin is recommended (grade B). The duration of prophylaxis is 3 months in patients with a motor deficit (grade C). No prophylaxis is recommended after discectomy or limited laminectomy in patients without additional risk factors. Mechanical methods are recommended after spinal fusion or extended laminectomy. For patients with additional risk factors a low molecular weight heparin is recommended.     

Systematic review of thromboprophylaxis in colorectal surgery – an update

OBJECTIVE: The incidence of thromboembolism after colorectal surgery is higher than after general surgery. The aim of this paper is to update a systematic review addressing thrombosis prophylaxis in connection with colorectal surgery. METHODS: MEDLINE, EMBASE, LILACS, abstract books and reference lists from reviews were searched without language restrictions for randomized controlled trials or clinical controlled trials comparing prophylactic interventions and/or placebo up til August 2003. Five hundred and fifty-eight studies were identified of which 19 fulfilled the inclusion criteria. Data extraction was done by at least two of the authors. Outcome was deep venous thrombosis and/or pulmonary embolism diagnosed by various methods. RESULTS: Any kind of heparin is better than no treatment or placebo (11 studies) with a Peto Odds ratio (POR) at 0.32 (95% CI 0.20-0.53). Unfractionated heparin and low molecular weight heparin (4 studies) were equally effective POR 1.01 (95% CI 0.67-1.52). The combination of graduated compression stockings and LMWH is better than LMWH alone (2 studies) with a POR at 4.17 (95% CI 1.37-12.70). CONCLUSION: The optimal thromboprophylaxis in colorectal surgery is the combination of graduated compression stockings and low-dose unfractionated heparin or low molecular weight heparin.     

Randomized clinical trial of low molecular weight heparin with thigh-length or knee-length antiembolism stockings for patients undergoing surgery

BACKGROUND: This was a randomized clinical trial to determine the efficacy and safety of a 'blanket' protocol of low molecular weight heparin (LMWH) and the best length of antiembolism stocking, for every patient requiring surgery under general anaesthesia. METHODS: Of 426 patients interviewed, 376 agreed to be randomized to receive one of three types of stocking: thigh-length Medi thrombexin climax (Medi UK, Hereford, UK), knee-length thrombexin climax and thigh-length Kendall T.E.D. (Tyco Healthcare UK, Redruth, UK). All patients received LMWH thromboprophylaxis. Duplex ultrasonography was used to assess the incidence of postoperative deep vein thrombosis (DVT). RESULTS: No postoperative DVT occurred in 85 patients at low or moderate risk. Nineteen DVTs occurred, all in the 291 high-risk patients: two with the Medi thigh-length stockings, 11 with the Medi knee-length stockings (odds ratio 0.18 (95 per cent confidence interval 0.04 to 0.82); P = 0.026) and six with the Kendall T.E.D. thigh-length stockings. No patient developed a pulmonary embolism. Stocking groups were similar for age, sex, thromboembolic risk, type of operation and compliance. One significant bleeding complication occurred. CONCLUSION: A single protocol comprising LMWH and thigh-length stockings abolished DVT in low- and moderate-risk patients, and reduced the rate of DVT to 2 per cent in high-risk patients.     

Thromboprophylaxis in patients undergoing surgery for breast cancer

Patients undergoing surgery for carcinoma of the breast are thought to be at lower risk of developing thromboembolic complications than those with abdominal malignancies and the role of the thromboprophylaxis is unproven. To determine current thromboprophylaxis practice a questionnaire was sent to 184 consultant surgeons thought to be involved in breast cancer surgery, of whom 137 responded (74%). Eleven surgeons no longer dealt with breast cancer patients. Of the remaining 126, thromboprophylaxis was given routinely by 88 (69.8%), with the commonest regimens being subcutaneous heparin only (n=43) and heparin combined with compression stockings (n=20). Patients with breast cancer were regarded as being at high risk of thromboembolic complications by 65 clinicians in this group (73.7%). Thirty-eight consultants did not use thromboprophylaxis routinely, the most commonly stated reasons were low/no risk of DVT (n=24), because of early postoperative mobilization (n=20) and increased risk of bleeding complications (n=15). Twenty clinicians reported a total of 22 deep venous thromboses and two pulmonary emboli affecting patients under their care who had surgery for breast cancer during the preceding year. Almost 70% of surgeons routinely employ thromboprophylaxis in patients undergoing breast cancer surgery but practice varies widely.     

Thoracic surgery for patients with deep vein thrombosis

Deep vein thrombosis (DVT) is a main cause of pulmonary thromboembolism (PTE), and therefore both diseases are categorized as a serial pathophysiology of venous thromboembolism (VTE). Treatment goals for DVT include stopping clot propagation and preventing the recurrence of thrombus, the occurrence of PTE, and the development of pulmonary hypertension, which can be a complication of multiple recurrent pulmonary emboli. Clinical guidelines stratify the risk of VTE to 4 levels and recommend the treatment options. In high or extremely high risk patients for VTE, the use of low-dose heparin is recommended. The prevention against VTE, such as elastic compression stockings and intermittent sequential pneumatic leg compression( ISPC), is the most important prophylactic treatment against perioperative PTE by reducing thrombotic risk in low or moderate high risk patients for VET. Since there is no clear evidence that screening all or even selected patients for thrombophilias improves long-term outcomes, the physician's clinical judgment, and consultation with appropriate subspecialists should guide management perioperatively. Once PTE is suspected, immediate and accurate diagnosis and appropriate treatment are mandatory.     

Recommendations for the peri-operative management of bariatric surgery patients: results of a national survey

To standardise possible peri-operative bariatric surgery protocols, a survey was prepared to be filled in by members of the Spanish Society for Obesity (Sociedad Española de Cirugía de la Obesidad) (SECO), and to approve it at the XII National Congress. A total of 47 members of SECO from 14 autonomous communities responded, and it unanimously approved by the Congress. As highly recommended peri-operative procedures, were proposed: full laboratory analysis (98%) with an endocrine study (90%), ECG (96%), chest x-ray (98%), an oesophageal-gastric imaging test (endoscopy or gastro-duodenal transit study (98%), antibiotic prophylaxis (92%) and use of low molecular weight heparins pre-operatively (96%), and for 2 weeks (83%). Pre-surgical, abdominal ultrasound (86%), spirometry (80%), diet (88%) and psychological study (76%), and during surgery, use of elastic stockings (76%), leak tests (92%) and drainages (90%), were established as advisable procedures.