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Continuing warfarin during cutaneous surgery
original article P. Sugden H. Siddiqui Department of Plastic Surgery, James Cook University Hospital, Middlesbrough Correspondence to: Mr Paul Sugden, Th Thee Ol Old d Barn, Thornley eyy, To Tow w La Law Law County Durrha ham, DL13 4PA Tel: +44 (0)191 2829682 Email: surgeo [email protected]
CONTINUING WARFARIN DURING CUTANEOUS SURGERY The risk of haemorrhage from minor cutaneous surgical procedures has long been a concern in the treatment of patients receiving warfarin as anti-coagulation therapy. Interruption, alteration, hospital admission and monitoring have resource implications as well as the potential for complications. Therefore, we wanted to determine whether it was feasible to undertake typical minor plastic surgery procedures without altering patients’ warfarin dosage regimens. We undertook a prospective study of 51 patients (age range 36 to 86), with 78 wounds, undergoing a range of minor cutaneous surgical procedures including excision biopsies, local aps and skin grafts. The patients continued their normal warfarin regimen and the INR was checked on the day of surgery, ranging from 1.1 to 4.0. There were no problems encountered during surgery, but two patients presented with bleeding from a wound a few days post-operatively. We feel that it is unnecessary to modify warfarin regimens for minor cutaneous surgery. However, a well-briefed patient and experienced surgical management with good support facilities are a prerequisite for this. keywords: Warfarin, anticoagulant, cutaneous surgery Surgeon, 1 June 2008 148-50
Introduction Coagulation is a major defence against bleeding and is countered by inhibitory pathways in a delicate homeostatic balance. A disorder of one of three factors – intimal injury changes in the blood’s coagulation properties and alterations of blood fl flow – can lead to the pathogenesis of thrombosis and a classically referred to as Virchow’s triad. Although Virchow was referring to venous thrombosis, this pathological process can be applied to arterial thrombosis.1 The consequences of thrombosis may be local, such as deep vein thrombosis, or distant, such as cerebrovascular accidents or pulmonary embolism.2 In routine outpatient practice only one of Virchow’s triad is amenable to manipulation, the blood’s coagulation properties, for which oral anti-coagulants are used. Th The most commonly encountered drug used is warfarin, which is an antagonist of vitamin K that inhibits vitamin K epoxide reductase and possibly vitamin K reductase. This limits the carboxylation of the vitamin K-dependent coagulation factors (prothrombin, factors VII, IX and X) as well as some anticoagulant proteins (proteins C and S). It is by interfering with these clotting factors that warfarin exerts its anti-thrombotic eff ffect.3,4 Th The aim is to reduce the coaguability of blood to a therapeutic range based 148 |
the royal colleges of surgeons of edinburgh and ireland
on the indication at the expense of exposure to an increased risk of spontaneous bleeding.5 An increasing number of people are being prescribed warfarin and the most commonly encountered indications are deep venous thrombosis (DVT), prosthetic heart valves and atrial fibrilfi lation. Its effect ff is measured by the international normalized ratio (INR), the ideal level determined by the indication.4-6 Previous studies in oral, ophthalmic cutaneous and plastic surgery have suggested that minimally invasive procedures can be safely undertaken if a patient’s normal warfarin regimen is continued.711,15,16 However, those examining cutaneous procedures either have not been representative of typical cutaneous procedures encountered in plastic surgery, or have not qualified fi the types of cases included. Th Therefore, we wanted to determine whether it was safe and practicable to undertake minor cutaneous surgery whilst patients continued their normal warfarin dosage regimen.
Methods Th study was prospective and under the guidance The of a single consultant plastic surgeon lasting for 2.5 years. Only patients with a stable INR no greater than four at the initial consultation were included, © 2008 Surgeon 6; 3: 148-50
Table 1. Indications for warfarin treatment
Table 2. Closure method employed in study
Indication
Number
Closure
Number
Atrial brillation
32
Direct closure
48
DVT
7
Full thickness skin graft
10
CVA
4
Local ap
5
Prosthetic heart valve
3
Split thickness skin graft
3
DVT/Pulmonary embolism
2
Secondary intention
2
DVT/Atrial brillation
2
Total
68
Aortic aneurysm
1
Aortic aneurysm
1
Total
51
Total
51
Table 3. Complications encountered in study Age
Warfarin indication
INR
Diagnosis
Operation
Complication
Outcome
70
AF
2.5
BCC face
Local ap
Bleeding at 3 days and partial ap necrosis
Healed without intervention
70
DVT
3.9
BCC leg
Split thickness skin graft
Late loss of graft
Healed by secondary intention
65
AF
2.5
SCC scalp
Split thickness skin graft
Haematoma and loss of graft
Healed by secondary intention
Discussion as the risks of bleeding complications increase when the INR is 5.0 or greater (measured on the day of surgery).6 All procedures were performed under local anaesthetic using lignocaine and adrenaline. The skin was infi Th filtrated at least 10 minutes pre-operatively, during which time the next patient was counselled and consented. Postoperatively, a light pressure dressing was applied and the patient was kept in the department for a couple of hours to check for any bleeding. All patients were seen at least once in outpatients irrespective of the histological diagnosis.
Results Th study included 51 patients, with a mean age of 73 (range 38 The to 88). The Th indications for surgery were benign and malignant skin lesions, as well as hand surgery. Th The indications for warfarin treatment are shown in Table 1, the most common being atrial fi fibrillation, and the INR range was 1.1 to 4.0 (mean and median 2.4). There Th were 68 primary defects with closure methods including direct, local flaps and skin grafts (Table 2) resulting in a total of 78 wounds with the donor defect included. The size of defect closed ranged from 3x3mm to 7x8cm, with 26 2x2cm defects and 21 3x5cm being the most common. There were three complications (Table 3), all in male patients, Th but one of these was not related to bleeding and all healed with no further surgical intervention or bleeding. © 2008 Surgeon 6; 3: 148-50
Th risk of haemorrhage from minor cutaneous surgical procedures The has long been a concern in the treatment of patients receiving warfarin as anti-coagulant therapy. Whilst most would agree that in patients undergoing major surgery conversion to heparin is the optimal treatment, there is no consensus for patients undergoing minor surgery. The options, depending on the indication, are no change in warfarin Th dosage, no change and ‘local measures’ (tranexamic acid or fibrin fi sealant), temporary cessation and conversion to heparin.7 However, all of these have potential complications, such as if the plan is to stop warfarin then thromboembolism can occur, due to either suboptimal anticoagulation or rebound hypercoagulability.4,11 Whilst precise figures are diffi fficult to determine, it has been suggested that the risk of a cerebrovascular accident after temporarily discontinuing warfarin is up to 0.3% in AF and 6% in the fi first month of a DVT.11 If the patient is converted to heparin then, for what is in reality minor surgery, hospital admission is necessary (both whilst the INR falls and until it reaches the therapeutic level) leading to bed blockages, inconvenience, utilisation of resources and the potential for hospital acquired infections. Though Th previous studies have suggested that warfarin does not need to be discontinued for minor procedures, the case mix has not been representative of that found in plastic surgical practice or have not been qualified. fi The cases in our study are those typically encountered in a day case setting, including skin grafts and fl flaps.
the royal colleges of surgeons of edinburgh and ireland | 149
Whilst it is arguable that for some indications, such as AF, cessation for a few days pre-operatively may be practicable and safe, in our series we continued warfarin dosing irrespective of the indication. Two variables make it diffi fficult to predict on an individual basis the likely INR after stopping medication for a few days. First, the range of INRs in this series was surprisingly large and we have no reason to feel that this sample should be unique in this respect. Second, patients have diff ffering sensitivities to warfarin and so there should be a variable length of time for the INR to fall following cessation.3 Post-operatively, warfarin will need to be recommenced and it is diffi fficult to accurately assess how and when this should be done; increased monitoring is necessary and there is a greater potential for mis-dosing. Th Therefore, we felt that one common protocol for all cases would lead to less confusion, both for patients and staff, ff with a more predictable and smoother INR profi file as well as less impact on resources needed. Furthermore, whilst the risks of stopping warfarin for a few days are small they are still present and therefore they are likely to be reduced if normal warfarin dosage is continued. Balanced against this is the potential for bleeding complications that resulted in one reconstructive failure (split thickness skin graft) and potentially contributed to a partial failure (partial flap necrosis) in our series. All patients should be fully counselled pre-operatively about potential surgical complications and this should perhaps also include the risks related to the cessation of warfarin. A patient counselled may feel that whilst the likelihood of a bleeding complication is greater than that of a thromboembolic complication, the difference ff in morbidity and mortality means that they would choose to continue with warfarin throughout surgical treatment. Five wounds were treated by secondary intention, three of these in patients with complications. A raised INR does not remove this surgical option and, even if a complication occurs, wounds can be successfully managed open with no modifications of the normal methods of treating such wounds. Therefore, we continue to endorse that minor to moderate Th sized cutaneous defects in skin surgery do not overwhelm the haemostatic capabilities of the body’s coagulation system. This Th is not suitable for all cases as we feel that the INR should be stable and the patient well informed and counselled. Furthermore, adequate local measures should be undertaken and the surgeon should be suffi fficiently experienced with adequate infrastructure to support the post-operative care.
Copyright © 1 June 2008
150
|
REFERENCES 1. Makin A, Silverman SH, Lip GY. Peripheral vascular disease and Virchow’s triad for thrombogenesis. QJM 2002; 95: 199-210 2. Dunn AS, Turpie AG. Perioperative management of patients receiving oral anticoagulants: a systematic review. Arch Intern Medd 2003; 163: 901-8 3. Hirsh J, Dalen JE, Anderson DR et al. Oral anticoagulants: mechanism of action, clinical effectiveness, and optimal therapeutic range. Chest 1998; 114: 445S69S 4. Guidelines on oral anticoagulation: second edition. British Society for Haematology. British Committee for Standards in Haematology. Haemostasis and Thrombosis Task Force. J Clin Patholl 1990; 43: 177-83 5. Guidelines on oral anticoagulation: third edition. Br J Haematoll 1998; 101: 374-87. 6. Rose PE. Audit of anticoagulant therapy. J Clin Pathol 1996; 49: 5-9 7. Carter G, Goss AN, Lloyd J, Tocchetti R. Current concepts of the management of dental extractions for patients taking warfarin. Aust Dent J 2003; 48: 89-96 8. Wahl MJ. Dental surgery in anticoagulated patients. Arch Intern Medd 1998; 158: 1610-16 9. Souto JC, Oliver A, Zuazu-Jausoro I et al. Oral surgery in anticoagulated patients without reducing the dose of oral anticoagulant: a prospective randomized study. J Oral Maxillofac Surgg 1996; 54: 27-32 10. Bartley GB. Oculoplastic surgery in patients receiving warfarin: suggestions for management. Ophthal Plastic Reconstr Surgg 1996; 12: 229-30 11. Spandorfer J. The management of anticoagulation before and after procedures. Med Clin North Am 2001; 85: 1109-16 12. Ah-Weng A, Natarajan S, Velangi S and Langtry JA. Preoperative monitoring of warfarin in cutaneous surgery. Br J Dermatol 2003; 149: 386-9 13. Alcalay J. Cutaneous surgery in patients receiving warfarin therapy. Dermatol Surg 2001; 27: 756-8 14. Goldsmith SM, Leshin B, Owen J. Management of patients taking anticoagulants and platelet inhibitors prior to dermatologic surgery. J Dermatol Surg Oncol 1993; 19: 578-81 15. Stables G, Lawrence CM. Management of patients taking anticoagulant, aspirin, non-steroidal antiinammatory and other anti-platelet drugs undergoing dermatological surgery. Clin Exp Dermatoll 2002; 27: 432-35 16. Lam J, Lim J, Clark J et al. Warfarin and cutaneous surgery: a preliminary prospective study. Br J Plastic Surgg 2001; 54: 372-3
the royal colleges of surgeons of edinburgh and ireland
© 2008 Surgeon 6; 3: 148-50
CONTINUING WARFARIN DURING CUTANEOUS SURGERY The risk of haemorrhage from minor cutaneous surgical procedures has long been a concern in the treatment of patients receiving warfarin as anti-coagulation therapy. Interruption, alteration, hospital admission and monitoring have resource implications as well as the potential for complications. Therefore, we wanted to determine whether it was feasible to undertake typical minor plastic surgery procedures without altering patients’ warfarin dosage regimens. We undertook a prospective study of 51 patients (age range 36 to 86), with 78 wounds, undergoing a range of minor cutaneous surgical procedures including excision biopsies, local aps and skin grafts. The patients continued their normal warfarin regimen and the INR was checked on the day of surgery, ranging from 1.1 to 4.0. There were no problems encountered during surgery, but two patients presented with bleeding from a wound a few days post-operatively. We feel that it is unnecessary to modify warfarin regimens for minor cutaneous surgery. However, a well-briefed patient and experienced surgical management with good support facilities are a prerequisite for this. keywords: Warfarin, anticoagulant, cutaneous surgery Surgeon, 1 June 2008 148-50
Introduction Coagulation is a major defence against bleeding and is countered by inhibitory pathways in a delicate homeostatic balance. A disorder of one of three factors – intimal injury changes in the blood’s coagulation properties and alterations of blood fl flow – can lead to the pathogenesis of thrombosis and a classically referred to as Virchow’s triad. Although Virchow was referring to venous thrombosis, this pathological process can be applied to arterial thrombosis.1 The consequences of thrombosis may be local, such as deep vein thrombosis, or distant, such as cerebrovascular accidents or pulmonary embolism.2 In routine outpatient practice only one of Virchow’s triad is amenable to manipulation, the blood’s coagulation properties, for which oral anti-coagulants are used. Th The most commonly encountered drug used is warfarin, which is an antagonist of vitamin K that inhibits vitamin K epoxide reductase and possibly vitamin K reductase. This limits the carboxylation of the vitamin K-dependent coagulation factors (prothrombin, factors VII, IX and X) as well as some anticoagulant proteins (proteins C and S). It is by interfering with these clotting factors that warfarin exerts its anti-thrombotic eff ffect.3,4 Th The aim is to reduce the coaguability of blood to a therapeutic range based 148 |
the royal colleges of surgeons of edinburgh and ireland
on the indication at the expense of exposure to an increased risk of spontaneous bleeding.5 An increasing number of people are being prescribed warfarin and the most commonly encountered indications are deep venous thrombosis (DVT), prosthetic heart valves and atrial fibrilfi lation. Its effect ff is measured by the international normalized ratio (INR), the ideal level determined by the indication.4-6 Previous studies in oral, ophthalmic cutaneous and plastic surgery have suggested that minimally invasive procedures can be safely undertaken if a patient’s normal warfarin regimen is continued.711,15,16 However, those examining cutaneous procedures either have not been representative of typical cutaneous procedures encountered in plastic surgery, or have not qualified fi the types of cases included. Th Therefore, we wanted to determine whether it was safe and practicable to undertake minor cutaneous surgery whilst patients continued their normal warfarin dosage regimen.
Methods Th study was prospective and under the guidance The of a single consultant plastic surgeon lasting for 2.5 years. Only patients with a stable INR no greater than four at the initial consultation were included, © 2008 Surgeon 6; 3: 148-50
Table 1. Indications for warfarin treatment
Table 2. Closure method employed in study
Indication
Number
Closure
Number
Atrial brillation
32
Direct closure
48
DVT
7
Full thickness skin graft
10
CVA
4
Local ap
5
Prosthetic heart valve
3
Split thickness skin graft
3
DVT/Pulmonary embolism
2
Secondary intention
2
DVT/Atrial brillation
2
Total
68
Aortic aneurysm
1
Aortic aneurysm
1
Total
51
Total
51
Table 3. Complications encountered in study Age
Warfarin indication
INR
Diagnosis
Operation
Complication
Outcome
70
AF
2.5
BCC face
Local ap
Bleeding at 3 days and partial ap necrosis
Healed without intervention
70
DVT
3.9
BCC leg
Split thickness skin graft
Late loss of graft
Healed by secondary intention
65
AF
2.5
SCC scalp
Split thickness skin graft
Haematoma and loss of graft
Healed by secondary intention
Discussion as the risks of bleeding complications increase when the INR is 5.0 or greater (measured on the day of surgery).6 All procedures were performed under local anaesthetic using lignocaine and adrenaline. The skin was infi Th filtrated at least 10 minutes pre-operatively, during which time the next patient was counselled and consented. Postoperatively, a light pressure dressing was applied and the patient was kept in the department for a couple of hours to check for any bleeding. All patients were seen at least once in outpatients irrespective of the histological diagnosis.
Results Th study included 51 patients, with a mean age of 73 (range 38 The to 88). The Th indications for surgery were benign and malignant skin lesions, as well as hand surgery. Th The indications for warfarin treatment are shown in Table 1, the most common being atrial fi fibrillation, and the INR range was 1.1 to 4.0 (mean and median 2.4). There Th were 68 primary defects with closure methods including direct, local flaps and skin grafts (Table 2) resulting in a total of 78 wounds with the donor defect included. The size of defect closed ranged from 3x3mm to 7x8cm, with 26 2x2cm defects and 21 3x5cm being the most common. There were three complications (Table 3), all in male patients, Th but one of these was not related to bleeding and all healed with no further surgical intervention or bleeding. © 2008 Surgeon 6; 3: 148-50
Th risk of haemorrhage from minor cutaneous surgical procedures The has long been a concern in the treatment of patients receiving warfarin as anti-coagulant therapy. Whilst most would agree that in patients undergoing major surgery conversion to heparin is the optimal treatment, there is no consensus for patients undergoing minor surgery. The options, depending on the indication, are no change in warfarin Th dosage, no change and ‘local measures’ (tranexamic acid or fibrin fi sealant), temporary cessation and conversion to heparin.7 However, all of these have potential complications, such as if the plan is to stop warfarin then thromboembolism can occur, due to either suboptimal anticoagulation or rebound hypercoagulability.4,11 Whilst precise figures are diffi fficult to determine, it has been suggested that the risk of a cerebrovascular accident after temporarily discontinuing warfarin is up to 0.3% in AF and 6% in the fi first month of a DVT.11 If the patient is converted to heparin then, for what is in reality minor surgery, hospital admission is necessary (both whilst the INR falls and until it reaches the therapeutic level) leading to bed blockages, inconvenience, utilisation of resources and the potential for hospital acquired infections. Though Th previous studies have suggested that warfarin does not need to be discontinued for minor procedures, the case mix has not been representative of that found in plastic surgical practice or have not been qualified. fi The cases in our study are those typically encountered in a day case setting, including skin grafts and fl flaps.
the royal colleges of surgeons of edinburgh and ireland | 149
Whilst it is arguable that for some indications, such as AF, cessation for a few days pre-operatively may be practicable and safe, in our series we continued warfarin dosing irrespective of the indication. Two variables make it diffi fficult to predict on an individual basis the likely INR after stopping medication for a few days. First, the range of INRs in this series was surprisingly large and we have no reason to feel that this sample should be unique in this respect. Second, patients have diff ffering sensitivities to warfarin and so there should be a variable length of time for the INR to fall following cessation.3 Post-operatively, warfarin will need to be recommenced and it is diffi fficult to accurately assess how and when this should be done; increased monitoring is necessary and there is a greater potential for mis-dosing. Th Therefore, we felt that one common protocol for all cases would lead to less confusion, both for patients and staff, ff with a more predictable and smoother INR profi file as well as less impact on resources needed. Furthermore, whilst the risks of stopping warfarin for a few days are small they are still present and therefore they are likely to be reduced if normal warfarin dosage is continued. Balanced against this is the potential for bleeding complications that resulted in one reconstructive failure (split thickness skin graft) and potentially contributed to a partial failure (partial flap necrosis) in our series. All patients should be fully counselled pre-operatively about potential surgical complications and this should perhaps also include the risks related to the cessation of warfarin. A patient counselled may feel that whilst the likelihood of a bleeding complication is greater than that of a thromboembolic complication, the difference ff in morbidity and mortality means that they would choose to continue with warfarin throughout surgical treatment. Five wounds were treated by secondary intention, three of these in patients with complications. A raised INR does not remove this surgical option and, even if a complication occurs, wounds can be successfully managed open with no modifications of the normal methods of treating such wounds. Therefore, we continue to endorse that minor to moderate Th sized cutaneous defects in skin surgery do not overwhelm the haemostatic capabilities of the body’s coagulation system. This Th is not suitable for all cases as we feel that the INR should be stable and the patient well informed and counselled. Furthermore, adequate local measures should be undertaken and the surgeon should be suffi fficiently experienced with adequate infrastructure to support the post-operative care.
Copyright © 1 June 2008
150
|
REFERENCES 1. Makin A, Silverman SH, Lip GY. Peripheral vascular disease and Virchow’s triad for thrombogenesis. QJM 2002; 95: 199-210 2. Dunn AS, Turpie AG. Perioperative management of patients receiving oral anticoagulants: a systematic review. Arch Intern Medd 2003; 163: 901-8 3. Hirsh J, Dalen JE, Anderson DR et al. Oral anticoagulants: mechanism of action, clinical effectiveness, and optimal therapeutic range. Chest 1998; 114: 445S69S 4. Guidelines on oral anticoagulation: second edition. British Society for Haematology. British Committee for Standards in Haematology. Haemostasis and Thrombosis Task Force. J Clin Patholl 1990; 43: 177-83 5. Guidelines on oral anticoagulation: third edition. Br J Haematoll 1998; 101: 374-87. 6. Rose PE. Audit of anticoagulant therapy. J Clin Pathol 1996; 49: 5-9 7. Carter G, Goss AN, Lloyd J, Tocchetti R. Current concepts of the management of dental extractions for patients taking warfarin. Aust Dent J 2003; 48: 89-96 8. Wahl MJ. Dental surgery in anticoagulated patients. Arch Intern Medd 1998; 158: 1610-16 9. Souto JC, Oliver A, Zuazu-Jausoro I et al. Oral surgery in anticoagulated patients without reducing the dose of oral anticoagulant: a prospective randomized study. J Oral Maxillofac Surgg 1996; 54: 27-32 10. Bartley GB. Oculoplastic surgery in patients receiving warfarin: suggestions for management. Ophthal Plastic Reconstr Surgg 1996; 12: 229-30 11. Spandorfer J. The management of anticoagulation before and after procedures. Med Clin North Am 2001; 85: 1109-16 12. Ah-Weng A, Natarajan S, Velangi S and Langtry JA. Preoperative monitoring of warfarin in cutaneous surgery. Br J Dermatol 2003; 149: 386-9 13. Alcalay J. Cutaneous surgery in patients receiving warfarin therapy. Dermatol Surg 2001; 27: 756-8 14. Goldsmith SM, Leshin B, Owen J. Management of patients taking anticoagulants and platelet inhibitors prior to dermatologic surgery. J Dermatol Surg Oncol 1993; 19: 578-81 15. Stables G, Lawrence CM. Management of patients taking anticoagulant, aspirin, non-steroidal antiinammatory and other anti-platelet drugs undergoing dermatological surgery. Clin Exp Dermatoll 2002; 27: 432-35 16. Lam J, Lim J, Clark J et al. Warfarin and cutaneous surgery: a preliminary prospective study. Br J Plastic Surgg 2001; 54: 372-3
the royal colleges of surgeons of edinburgh and ireland
© 2008 Surgeon 6; 3: 148-50