Thromboembolic disease in patients undergoing total knee replacement

In a prospective study fo the incidence of deep-vein thrombosis in thirty patients undergoing total knee replacement, all patients had clinical examinations and 125I fibrinogen scanning, while those suspected of having deep venous thrombosis also had confirmatory venography. Sixteen (53 per cent) of the thirty patients had thromboembolic disease; nine had thrombi only in the limb operated on; four had bilateral deep venous thrombi; and three had pulmonary embolism. In nine patients who took aspirin regularly the incidence of thromboembolism was 11 per cent, while in the eight who did not take aspirin or any other antiplatelet drug the incidence was 88 per cent, a difference which was highly significant (p = 0.003).     

Prevention of deep-vein thrombosis after total hip arthroplasty. Comparison of warfarin and dalteparin

The effectiveness and safety of warfarin were compared with those of a low-molecular-weight heparin (dalteparin) for the prevention of deep-vein thrombosis after total hip arthroplasty in a prospective, randomized, multi-institutional trial. Patients who were older than eighteen years of age and were scheduled to have an elective primary or revision total hip arthroplasty were eligible; 580 patients were randomized, 550 had the operation and received prophylaxis, and 382 had evaluable venograms. Prophylaxis was provided either with warfarin beginning the night before the operation or with dalteparin beginning two hours before the operation and was continued until venography was performed. Bleeding was assessed on the basis of intraoperative blood loss, transfusion requirements, a decrease in hematocrit, and clinically identified bleeding complications. The prevalence of deep-vein thrombosis was found to be significantly lower in the patients who had received dalteparin than in those who had received warfarin (twenty-eight [15 per cent] of 192 patients compared with forty-nine [26 per cent] of 190 patients; p = 0.006). Deep-vein thrombosis occurred in the calf veins of twenty-one patients (11 per cent) who had received dalteparin and of forty-three patients (23 per cent) who had received warfarin; this difference was significant (p = 0.003). Proximal deep-vein thrombosis occurred in ten patients (5 per cent) who had received dalteparin and in sixteen patients (8 per cent) who had received warfarin; however, with the numbers available, no significant difference could be detected (p = 0.185). We also could not detect a significant difference with regard to the intraoperative and postoperative blood loss, the decrease in hematocrit, and the prevalence of major bleeding complications between the two groups; however, the patients who had received dalteparin had a significantly higher prevalence of bleeding complications involving the operative site (p = 0.03), and a significantly greater percentage required postoperative transfusions (p = 0.001). We concluded that preoperative prophylaxis with dalteparin is significantly more effective than that with warfarin in preventing deep-vein thrombosis after total hip arthroplasty. The greater effectiveness of dalteparin must be considered, however, in light of an increased need for postoperative transfusions and an increase in the prevalence of wound-related bleeding complications.     

Danaparoid in the prevention of thromboembolic complications

OBJECTIVE: To review the therapies used to prevent postoperative thromboembolic complications with a focus on the role of danaparoid, a new low-molecular-weight glycosaminoglycan. DATA SOURCES: A MEDLINE search was performed to identify pertinent English-language literature including studies, abstracts, and review articles. Key search terms included danaparoid, heparinoid, lomoparin, heparin, prophylaxis, thrombosis, embolism, thromboembolism, and thromboembolic and postoperative complications. The manufacturer of danaparoid was contracted for additional information related to this compound. STUDY SELECTION AND DATA EXTRACTION: All identified articles were reviewed for possible inclusion in this review. Comparisons primarily focused on data obtained from prospective, randomized, controlled, blind clinical trials. Another important consideration was the use of venography to determine the presence of deep venous thrombosis. DATA SYNTHESIS: Various therapies are available for the prevention of postoperative thromboembolic complications. Effective pharmacologic treatments currently available include adjusted-dose heparin, warfarin, aspirin, dextran, and low-molecular-weight heparins (LMWHs). Until recently, warfarin was considered the drug of choice for thromboprophylaxis in high-risk patients, including patients undergoing orthopedic surgical procedures. Because of their comparable efficacy and greater ease of use, LMWHs are gaining favor over warfarin in this patient population. In well-designed clinical trials involving patients undergoing elective total hip replacement or fractured hip surgery, danaparoid has demonstrated greater efficacy than other active treatments, including warfarin, dextran, aspirin, and heparin plus dihydroergotamine. While studies comparing danaparoid with LMWHs have not yet been published, danaparoid may be more useful in patients with heparin-associated thrombocytopenia. CONCLUSIONS: Danaparoid is an antithrombotic agent with characteristics that distinguish it from heparin and LMWHs. Based on the efficacy and safety data reviewed, danaparoid should be considered one of the drugs of choice for the prevention of thromboembolic complications in patients undergoing orthopedic hip procedures and the drug of choice for the management of any patient with heparin-induced thrombocytopenia who requires anticoagulant therapy.     

Treatment of arterial thromboembolic disease

Prevention of thrombus formation and embolization remains a therapeutic challenge. Recent advances in the treatment of arterial thromboembolic disease include prevention of thromboembolism in patients with nonrheumatic atrial fibrillation with warfarin or aspirin, and combined therapy with low-dose aspirin, and anticoagulants for prosthetic heart valves and coronary artery disease. The potential of direct thrombin inhibition for treatment of acute coronary syndromes is also discussed.     

Prophylaxis of venous thrombosis and pulmonary embolism in patients with acute traumatic spinal cord lesions

Twenty-one patients with acute traumatic spinal cord lesions who were admitted to our Spinal Unit during 1974 have been treated with Calcium Heparin, using a dosage of 5000-7500 i.u. at 12-hourly intervals from the first days after the lesion until the use of a wheelchair, as a prophylactic measure in order to prevent venous thromboembolism. Of these 21 patients 18 received this treatment continuously, with a resulting 0 per cent of venous thrombosis and 0 per cent of pulmonary embolisms. In the three remaining cases, treatment had to be temporarily interrupted and in one case clinical thrombo-phlebitis was clearly evident. No case of pulmonary embolism was registered. We consider this technique to be very useful in the prophylaxis of thrombo-embolic complications in this type of patient. The use of this type of prophylactic therapy, results and conclusions are discussed.     

Prevention of thromboembolic phenomena

The leading cause of death from total hip replacement is pulmonary embolism. Prophylactic anticoagulation has been effective in decreasing thromboembolic phenomena but has been associated with a high rate of complications. A low dose warfarin prophylaxis combined with anti-embolic hose, elevation of the legs and early ambulation was employed in 415 total hip replacements. Clinical thrombosis occurred in 2.4 per cent and there was 1.45 per cent pulmonary emboli but none resulted in death. Two deaths from non-embolic causes occurred for a mortality rate of 0.49 per cent. Systemic complications of the warfarin were few with 5 mild gastroentestinal hemorrhages but no deaths related to the medication. Wound hemorrhage occurred in 4.6 per cent of patients and it is recommended that severe, deep superficial hematomas be treated with early surgical evacuation. The management program appeared to be safe and effective in preventing postoperative mortality from pulmonary emboli but close monitoring is essential.     

Comparison of the use of a foot pump with the use of low-molecular-weight heparin for the prevention of deep-vein thrombosis after total hip replacement. A prospective, randomized trial

We conducted a prospective, randomized trial to compare the safety and effectiveness of the A-V Impulse System foot pump with that of low-molecular-weight heparin for reducing the prevalence of deep-vein thrombosis after total hip replacement. Of 290 patients who were to have a primary total hip replacement, 143 were randomized to receive enoxaparin (forty milligrams daily) for seven days after the operation and 147, to use the foot pump for seven days. The primary outcome measure was the prevalence of deep-vein thrombosis, as determined by venography on the sixth, seventh, or eighth postoperative day. Secondary outcome measures included transfusion requirements, intraoperative blood loss, postoperative drainage, blood-loss index, appearance of the site of the wound according to a subjective visual-analog scale, and swelling of the thigh. The patients' compliance with the regimen for use of the foot pump was monitored with an internal timing device, and their acceptance of the device was assessed with a questionnaire. Symptoms consistent with pulmonary embolism were investigated with ventilation-perfusion scanning. The patients were contacted later for detection of symptoms of venous thromboembolism that may have occurred during the first three months after discharge from the hospital. Venography was performed on 274 patients: 136 who used the foot pump and 138 who received enoxaparin. Deep-vein thrombosis was detected in twenty-four (18 per cent) of the patients who used the foot pump compared with eighteen patients (13 per cent) who received enoxaparin (95 per cent confidence interval for the difference in proportions, -3.9 to +13.0 per cent). Thrombosis in the calf was found in seven patients (5 per cent) in the former group compared with six patients (4 per cent) in the latter (95 per cent confidence interval for the difference, -4.2 to +5.8 per cent), and proximal thrombosis was observed in seventeen patients (13 per cent) in the former group compared with twelve patients (9 per cent) in the latter (95 per cent confidence interval for the difference, -3.5 to +11.1 per cent). None of these differences was significant. No patient in either group had major proximal deep-vein thrombosis; all proximal thrombi were isolated entities involving the femoral valve cusp and were of unknown importance. One patient who used the foot pump had a non-fatal pulmonary embolism. One patient who received enoxaparin had a symptomatic deep-vein thrombosis during hospitalization. Two patients (one from each group [0.7 per cent]) were readmitted to the hospital because of a symptomatic deep-vein thrombosis despite normal venographic findings at the time of discharge. There was no difference in the transfusion requirements or the intraoperative blood loss between the two groups. There were more soft-tissue side effects in the patients who received enoxaparin than in those who used the foot pump: there was more bruising of the thigh and oozing of the wound (p < 0.001 for each), postoperative drainage (578 compared with 492 milliliters; p = 0.014), and swelling of the thigh (twenty compared with ten millimeters; p = 0.03). Of 124 patients who used the foot pump and were asked about the acceptability of the device, fourteen (11 per cent) said that it was uncomfortable, twenty-one (17 per cent) reported sleep disturbance, and four (3 per cent) stated that they had stopped using the device. Conversely, ten (8 per cent) found it relaxing. We concluded that the foot pump is a suitable alternative to low-molecular-weight heparin for prophylaxis against thromboembolism after total hip replacement and that it produces fewer soft-tissue side effects. Tolerance of the device is a problem for some patients.     

Postoperative mortality after total hip arthroplasty. An analysis of deaths after two thousand seven hundred and thirty-six procedures

We retrospectively determined the prevalence and nature of mortality as many as ninety days after 2736 primary and revision total hip arthroplasties performed in 2002 patients by one surgeon at a teaching hospital between January 1969 and December 1996. All but seventy-one of the patients had received prophylaxis against venous thromboembolic disease. There were no intraoperative deaths, and no events during the operation could be linked directly to postoperative mortality. Eight deaths (mortality rate, 0.3 per cent) occurred within ninety days after the 2736 procedures. Four deaths (mortality rate, 0.15 per cent) occurred during the initial hospitalization. The cause of seven of the deaths was determined. Three patients died as a result of preexisting disease (severe hepatorenal disease, metastatic esophageal cancer, or severe cardiac disease), and one patient died from sepsis with a gram-negative organism during a thoracotomy eight days postoperatively. A bleeding complication that occurred while the patient was receiving warfarin therapy led to the death of two other patients; one of these deaths occurred in 1974 and the other, in 1982. At the time that these patients were managed, the desired prothrombin time was considered to be twice the control value. The remaining patient, who had had a clip placed on the inferior vena cava after a pulmonary embolus occurred in 1970, died secondary to acute, severe thrombosis of this vessel after a total hip arthroplasty in 1971. The patient for whom the cause of death was not determined had had an artificial aortic valve and had been receiving chronic warfarin therapy. She died suddenly eighty-nine days postoperatively; no autopsy was performed. No patient died as the direct result of a known pulmonary embolus. No deaths related to venous thromboembolic disease or its prophylaxis or treatment occurred after 1982 (1458 operations). We attribute this, in part, to reduced levels of warfarin prophylaxis and improved management with warfarin. The ninety-day postoperative mortality rate after 2736 procedures performed over nearly three decades was low (0.3 per cent). This span of time included the period before the introduction of many current improvements in perioperative care, such as routine intubation of patients under general anesthesia, continuous monitoring of the electrocardiogram intraoperatively, and blood-gas determinations. When the patients who died as a result of known, severe preexisting disease were excluded, the mortality rate was 0.18 per cent (five of 2733).     

Reduced morbidity and mortality rates of the heparin-induced thrombocytopenia syndrome

PURPOSE: We reported a 61% morbidity rate and a 23% mortality rate for the heparin-induced thrombocytopenia (HIT) syndrome in 1983. We subsequently reported in 1987 that with early recognition, immediate cessation of the administration of heparin, and platelet function inhibition, the morbidity rate could be reduced to 23% and the mortality rate to 12%. One hundred recent cases of patients with heparin-associated antiplatelet antibodies (HAAb) have been reviewed to determine whether aggressive screening, early diagnosis, and alternate management could further reduce morbidity and mortality rates. METHODS: The consecutive records of 100 patients with positive platelet aggregation tests were reviewed. Sixty-six patients were male. The patients' ages ranged from 23 days to 92 years. The patients were from vascular (28), cardiothoracic (42), and other (30) services. HIT was suspected in patients who received heparin and had falling platelet counts, platelet counts less than 100,000/mm3, or new thromboembolic or hemorrhagic events. RESULTS: Heparin was not offered to six patients with known HAAb. Twelve patients were successfully treated with antiplatelet therapy and limited reexposure to heparin, and 75 patients were successfully treated with early diagnosis and prompt cessation of heparin. Alternate forms of anticoagulation therapy were used selectively. Seven patients had 11 complications. Three of the seven patients were treated successfully with warfarin anticoagulation and aspirin (2) or with aspirin alone (1). A fourth patient was treated with thrombectomy, hematoma evacuation, and aspirin. A fifth patient underwent thrombolysis and coronary angioplasty in addition to receiving warfarin and aspirin. The sixth patient required two thrombectomies and warfarin. A seventh patient required two thrombectomies and aspirin. HIT was responsible for one of 17 deaths. CONCLUSION: A 7.4% morbidity rate and a 1.1% mortality rate have been achieved in patients with HAAb by aggressive screening, early recognition of HIT, and prompt cessation of the administration of heparin. Platelet function inhibitors and other anticoagulants, including nonreacting low molecular weight heparin, are important adjuncts in the management of the thromboembolic disorders associated with HIT.     

Underutilization of warfarin in older persons with chronic nonvalvular atrial fibrillation at high risk for developing stroke

OBJECTIVE: To investigate the prevalence of the use of warfarin to maintain an international normalized ratio (INR) between 2.0 and 3.0 in older persons with chronic nonvalvular atrial fibrillation (AF), and without contraindications to warfarin, who are at high risk for developing new thromboembolic (TE) stroke. DESIGN: A retrospective analysis of charts from all older persons seen during 1997 at an academic hospital-based geriatrics practice. SETTING: An academic hospital-based geriatrics practice staffed by fellows in a geriatrics training program and full-time faculty geriatricians. PATIENTS: Three hundred eighty men and 1183 women, mean age 80+/-8 years (range 59 to 103 years), were included in the study. MEASUREMENTS AND MAIN RESULTS: Of 1563 persons studied, 141 (9%) had chronic nonvalvular AF. Of 141 persons with AF, 127 (90%) were at high risk for developing TE stroke because they had either a previous thromboembolism, congestive heart failure, or echocardiographic evidence of abnormal left ventricular systolic function; a systolic blood pressure >160 mm Hg; or they were women older than 75 years of age. Of the 127 persons with AF at high risk for developing TE stroke, three (2%) had contraindications to warfarin. Of the 124 persons with AF at high risk for developing TE stroke and no contraindications to warfarin, 61 (49%) were treated with warfarin to maintain an INR between 2.0 and 3.0, and 45 (36%) were treated with 325 mg aspirin daily. Of 14 persons with AF at low risk for developing TE stroke, one (7%) was treated with warfarin to maintain an INR between 2.0 and 3.0, and six (43%) were treated with 325 mg aspirin daily. CONCLUSIONS: Warfarin is underutilized as a treatment to maintain an INR between 2.0 and 3.0 in older persons with chronic nonvalvular AF at high risk for developing TE stroke.     

Audit of an anticoagulant clinic: doctor and patient knowledge

Oral anti-coagulation with warfarin is increasingly required in the prophylaxis and treatment of vascular thrombosis and embolism. Unless the degree of anti-coagulation is maintained in the narrow therapeutic range either serious bleeding or failure to prevent thromboembolism may occur. Complications may occur in up to 31% of patients. We randomly sampled 50 patients attending an anticoagulant clinic and interviewed them. We found the PTR between 2.0-4.0 in 70% patients. Their records indicated that they attended 0.9 +/- 0.5 times per month, but the patients themselves said that they had 2.4 +/- 1.7 visits per month, lasting on average 1.9 +/- 0.7 hours per visit. The mean duration of therapy was 4.3 +/- 5.4 years [range 1 month to 26 years]. Many patients perceived that they had received no education about warfarin (23%) while the majority 67% of the remainder said their doctor had educated them. Concomitant aspirin was avoided by 74% patients but 14% considered it safe in combination with warfarin; 49% patients believed that alcohol was safe in combination with warfarin. When asked about the colours and strengths of warfarin tablets, 37% of our sample were completely correct, 9% were completely incorrect and 54% were partly correct. In 16% patients they could not describe their current therapy. As doctors may adjust warfarin dosage for patients in terms of tablet colour, we asked a sample of junior doctors about the colours or strengths of warfarin tablets: 10% were completely correct, one doctor knew none of the colours or strengths and the remainder had a partial knowledge. These studies suggest that the majority of patients on warfarin are cautious about therapy and are safe in their practices. However, we feel that a significant minority may be at risk from complications because of inadequate knowledge. We suggest that improving patient understanding by education may reduce complications and lead to more stable control of anticoagulant therapy.     

Recurrence of venous thromboembolism in patients with familial thrombophilia

BACKGROUND: Treatment of patients with deep vein thrombosis and an antithrombin or protein C or S deficiency is based on case reports and personal experience. OBJECTIVE: To systematically assess the risk for recurrence of venous thromboembolism after a first episode in patients with these deficiencies, a literature review and retrospective family cohort study were performed. METHODS: For the literature review, the annual incidence of a first recurrent venous thromboembolism was assessed for each deficiency by dividing the number of venous thromboembolic events by the number of years at risk. For the family cohort study, 1- and 5-year cumulative incidences of first recurrence were calculated based on medical histories taken in relatives of consecutive patients in whom venous thromboembolism and a deficiency were diagnosed. RESULTS: For the literature review, the annual incidence of a first recurrent venous thromboembolism in patients with antithrombin or protein S deficiency ranged from 13% to 17% and 14% to 16%, respectively. For the family cohort study, the 1- and 5-year cumulative incidences of recurrent venous thromboembolism were 10% (95% confidence interval, 1%-19%) and 23% (95% confidence interval, 10%-36%), respectively. Warfarin sodium (Coumadin) prophylaxis was associated with 2 venous thromboembolic events in 141 years at risk (1.4% per year), in contrast with 19 events in 709 years at risk (2.7% per year) without prophylaxis (difference, -1.3%; 95% confidence interval, -3.5% to 1.0%). CONCLUSIONS: The annual incidence of recurrent venous thromboembolism is high during the first years following a first episode, but seems to decline thereafter. Therefore, our results challenge current practice of prescribing lifelong warfarin therapy after a first or second episode of venous thromboembolism in patients with antithrombin or protein C or S deficiency.     

Anticoagulation in children with mechanical valve prostheses

BACKGROUND: Clotting complications in patients with mechanical valve prostheses can be prevented with either warfarin sodium (Coumadin; DuPont, Wilmington, DE) or antiplatelet agents. In children, it is not known whether one treatment regimen is more effective or safe than the other. METHODS: We prospectively followed up 64 children and young adults (aged 18 years or younger at implantation) with a mechanical valve on the left side of the heart, from October 1986 through October 1996. Forty-eight patients were treated with Coumadin and 16 with aspirin and dipyridamole. The two groups were similar in age, sex, valve location and size, mean length of follow-up, and operative indication. There has been a total follow-up of 272 patient-years on Coumadin and 116 patient-years on aspirin and dipyridamole. RESULTS: There was no difference between the two groups in survival or freedom from thromboembolism. Bleeding occurred more often in the patients taking Coumadin, but this difference was not statistically significant. Analysis of the literature showed thromboembolism and bleeding rates to be similar in the patients receiving Coumadin and those receiving antiplatelet agents. CONCLUSIONS: Coumadin and the combination of aspirin plus dipyridamole provided similar protection against complications in this group of children and young adults with left-sided St. Jude (St. Paul, MN) mechanical valves. The choice between the two regimens may depend on other factors, such as patient preference and convenience.     

Intellectual level (IQ) in heterozygotes for phenylketonuria (PKU). Is the PKU gene also acting by means other than phenylalanine-blood level elevation?

Wound infection in 239 patients who underwent cholecystectomy were analyzed retrospectively. Seventeen per cent of the patients with acute cholecystitis had wound infection compared with 8.9 per cent of patients with chronic cholecystitis. Bacteriology of wound infections revealed Staphylococcus aureus in 76.4 per cent of the chronic cholecystitis group and in 12.5 per cent of the acute cholecystitis group. Wound infection in the acute cholecystitis group involved gram-negative rods predominantly. Organisms were isolated from bile culture in 71.4 per cent of acute cholecystitis patients compared with 59.6 per cent of chronic cholecystitis patients. Of patients with positive bile cultures 11.3 per cent had wound infections compared with 6.8 per cent of patients with negative bile cultures. The most common organisms isolated from bile cultures with resultant wound infections were S epidermis, S aureus, and Klebsiella sp. Wound infection after cholecystectomy for chronic cholecystitis arises from external sources and not contaminated bile. Antibiotic therapy should be directed accordingly.     

Thromboembolism complicating surgery for cervical and uterine malignancy: incidence, risk factors, and prophylaxis

Venous thromboembolism is a leading cause of death and morbidity after extended surgery for early malignancies of the cervix and uterus. Two hundred eighty-one patients who underwent such surgery were retrospectively evaluated for associated risk factors, the incidence of clinically significant thromboembolic complications, and prophylactic value of low-dose heparin and antiembolism stockings. Significant thromboemboli were encountered in 7.8% of patients postoperatively and accounted for the only 4 postoperative deaths. Forty-five percent of patients who developed thromboemboli did so after discharge from the hospital. The preoperative risk factors found to be associated with thromboembolism, in order of statistical significance, were weight in excess of 85.5 kg, advanced clinical stage of malignancy, and radiation therapy within 6 weeks of the operative procedure. Low-dose heparin therapy and the use of antiembolism stockings as preventative measures did not appear to reduce the incidence of thromboembolic complications. A prospective study will be necessary to evaluate definitely the effectiveness of various therapeutic modalities on thromboembolism in gynecologic oncology patients.     

Outpatient pacemaker procedures in orally anticoagulated patients

Reexamination of surgical practices in the present era of cost containment has led to increased outpatient procedures including pacemaker surgery. While the safety and economic benefits of outpatient pacemaker surgery in nonanticoagulated patients is well documented, results of pacemaker operations in patients maintained on coumadin for thromboembolic prophylaxis have not been evaluated. In patients where complications with pacemaker surgery appeared successive, we have established a low incidence of complications. Recently, we extended this approach to the outpatient setting; this report retrospectively reviews our 4-year experience. During the study period, 150 patients underwent outpatient pacemaker procedures, including 37 patients receiving oral warfarin. There was no difference in the incidence of wound related and wound unrelated complications between patients receiving warfarin and the nonanticoagulated cohort. In addition, no wound hematomas, blood transfusions, or clinically significant bleeding episodes were noted among warfarin recipients. We conclude that pacemaker surgery in patients receiving oral anticoagulation is safe and feasible. The use of the cephalic cutdown technique avoiding blind subclavian punctures, meticulous attention to pocket hemostasis, and the use of small caliber unipolar positive fixation leads appears warranted in this selected group of patients at high risk for perioperative bleeding.     

Prophylaxis for venous thromboembolism in head and neck surgery: the practice of otolaryngologists

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are an important cause of morbidity and mortality in the surgical patient. The first guideline produced by the Scottish Intercollegiate Guidelines Network was for the prophylaxis of venous thromboembolism. Patients undergoing major head and neck cancer surgery commonly exhibit risk factors for venous thromboembolism. Currently, however, there are no data on its incidence in these patients. A questionnaire survey was performed to assess the current practice of consultant otolaryngologists regarding DVT prophylaxis in patients undergoing head and neck cancer surgery. Of those respondents who managed these patients, 57 per cent did not use routine DVT prophylaxis while 43 per cent did. A wide variety of techniques were employed among those practising DVT prophylaxis. A consensus is needed concerning the use of thromboembolism prophylaxis in head and neck surgery patients.     

Appendicectomy: an assessment of the advisability of stump invagination

Seven hundred and thirty-two cases of appendicectomy performed over a period of 5 years are reviewed to compare the incidence of complications and the length of the postoperative stay in hospital, depending on whether the appendix stump was simply ligated or was invaginated by purse string suture following ligation. No detrimental effects are noted following simple ligation, whereas patients who had stump invagination remained in hospital on average more than a day longer, mainly owing to a higher incidence of wound infection (16 per cent as against 6 per cent).     

Neuropathology in the neurosciences. A system in transition

BACKGROUND: Despite the use of warfarin, major systemic embolism remains an important complication in patients with heart-valve replacement. Although the addition of antiplatelet agents has the potential to reduce this complication, their efficacy and safety when given in combination with warfarin are uncertain. METHODS: In a randomized, double-blind, placebo-controlled trial, we assessed the efficacy and safety of adding aspirin (100 mg per day) to warfarin treatment (target international normalized ratio, 3.0 to 4.5) in 370 patients with mechanical heart valves or with tissue valves plus atrial fibrillation or a history of thromboembolism. RESULTS: A total of 186 patients were randomly assigned to aspirin and 184 to placebo, and they were followed for up to 4 years (average, 2.5). Major systemic embolism or death from vascular causes occurred in 6 aspirin-treated patients (1.9 percent per year) and 24 placebo-treated patients (8.5 percent per year) (risk reduction with aspirin, 77 percent; 95 percent confidence interval, 44 to 91 percent; P < 0.001). Major systemic embolism, nonfatal intracranial hemorrhage, or death from hemorrhage or vascular causes occurred in 12 patients assigned to aspirin (3.9 percent per year) and 28 patients assigned to placebo (9.9 percent per year) (risk reduction, 61 per cent; 95 percent confidence interval, 24 to 80 percent; P = 0.005); major systemic embolism or death from any cause occurred in 13 patients (4.2 percent) and 33 patients (11.7 percent), respectively (risk reduction, 65 percent; 95 percent confidence interval, 33 to 82 percent; P < 0.001); and death from all causes occurred in 9 patients (2.8 percent) and 22 patients (7.4 percent), respectively (risk reduction, 63 percent; 95 percent confidence interval, 19 to 83 percent; P = 0.01). Bleeding occurred in 71 patients in the aspirin group (35.0 percent), as compared with 49 patients in the placebo group (22.0 percent) (increase in risk, 55 percent; 95 percent confidence interval, 8 to 124 percent; P = 0.02); major bleeding occurred in 24 and 19 patients, respectively (increase in risk, 27 percent; 95 percent confidence interval, -30 to 132 percent; P = 0.43). CONCLUSIONS: In patients with mechanical heart valves and high-risk patients with prosthetic tissue valves, the addition of aspirin to warfarin therapy reduced mortality, particularly mortality from vascular causes, together with major systemic embolism. Although there was some increase in bleeding, the risk of the combined treatment was more than offset by the considerable benefit.     

Antithrombotic therapy prescribed for patients with non-rheumatic atrial fibrillation

Patients with non-rheumatic atrial fibrillation have a fivefold increased risk of stroke. Warfarin reduces this risk by approximately two thirds, but evidence for benefit from aspirin is less compelling. We assessed whether our current practice reflects the message of the trials. In a retrospective case record study we reviewed notes of 131 patients with atrial fibrillation (AF), mean age 79 (range 53-95) years, admitted to a medical unit (72) or geriatric assessment unit (59). Thirty-two patients had paroxysmal AF. Of 115 patients with nonrheumatic AF, 36 (31%) had one or more recorded contraindication to anti-coagulation. Although 79 patients (69%) had no recorded contraindication to warfarin, only 2 took warfarin and 15 aspirin prior to admission. Ten patients commenced warfarin and 8 aspirin before discharge. Thirty-nine patients (53%) without contraindication, were discharged without antithrombotic therapy. Despite evidence to support anticoagulating patients with non-rheumatic AF, this rarely occurs.