Assessing the immediate and sustained effectiveness of circular epicardial surgical ligation of the left atrial appendage

Abstract Background/Aim: Obliterating the left atrial appendage from systemic circulation in patients with atrial fibrillation has been proposed to reduce thromboembolic events. The goal of this study was to assess the effectiveness of a circular method of epicardial surgical ligation in obliterating the left atrial appendage and maintaining sustained exclusion. Methods: Patients with permanent atrial fibrillation and an indication for elective cardiac surgery were enrolled. All patients underwent preoperative cardiac gated computerized tomography (CT) and transesophageal echocardiography (TEE). During the cardiac procedure circular ligation of the appendage was performed. Results: Twelve patients, mean (SD) age 65 (12) years completed the study. Intraoperative TEE demonstrated all patients (12/12) had complete postligation occlusion of the left atrial appendage. At three‐month follow‐up, cardiac gated CT demonstrated that 75% (9/12) of the patients had communication of contrast dye from the left atrial appendage to body of left atrium. Left atrial appendage orifice area and volume were reduced from mean (SD) (5.5 cm²[1.8] to 0.5 cm²[0.4] p = 0.002) and (14.0 cm³[8.3] to 2.7 cm³[1.3] p = .005) postligation, respectively. No clinically significant thromboembolic events were reported. Conclusions: Epicardial suture ligation of the left atrial appendage resulted in successful intra‐operative exclusion on TEE; however, a significant portion of patient's demonstrated communication of contrast on CT. This is suggestive of incomplete long‐term exclusion. The clinical significance of reduction in left atrial appendage orifice area and volume with a persistent communication requires further study.     

Evaluation of coagulation and fibrinolysis in haemodialysis patients at different haematocrit levels: Comparison between patients with and without diabetes

SUMMARY: There is an insufficient number of reports concerning the optimal haematocrit level for haemodialysis patients with diabetes. Although many reports have indicated that recombinant human erythropoietin (rHuEPO) therapy does not influence the incidence of intravascular thrombosis, no study has focused its attention on the difference of the coagulation-fibrinolysis system between haemodialysis patients with and without diabetes. We studied eight patients with diabetes and seven patients without diabetes who had been undergoing regular haemodialysis. In all 15 patients, rHuEPO administration was started at a haematocrit level of 20% and toe haematocrit tevels were gradually increased from 20 to 30%. Coagulation and fibrinolysis functions, measured at haematocrit levels of 20,25 and 30%, respectively, were compared between the two groups. In the diabetic group, platelet count, fibrinogen, thrombin-antithrombin III complex, frtmn/fibrinogen degradation products = D dimer, platelet factor 4 and platelet adhesion were statistically higher ( P < 0.05), and plasminogen and α2-plasmin inhibitor was statistically lower ( P < 0.05) than those in the non-diabetic group, even at the 20% level. These abnormalities at the baseline were extremely enhanced in connection with haematocrit increased by rHuEPO. the diabetic group, in particular, showed greater increases of platelet factor 4, platelet adhesion and thrombomodulin and a decrease of α2-plasmin inhibitor from the 20% to the 30% level ( P < 0.05) than the non-diabetic group. These findings suggest that haemodialysis patients with diabetes generally have enhanced thrombotic parameters compared with haemodialysis patients without diabetes, and the increase of haematocrit makes the difference greater. Accordingly, the target level of haematocrit for patients with diabetes should be set separately from that of patients without diabetes.     

Erythrocyte sedimentation rate, an underestimated tool in chronic renal failure

BACKGROUND.: Erythrocyte sedimentation rate is widely used in the generalpopulation. It has seldom been studied in patients with chronicrenal failure. The purpose of this study was to assess its usefulnessin haemodialysis patients. METHODS.: Forty-five haemodialysis patients with no evidence of acuteor chronic inflammatory illness were studied. Nine were diabetic,and 12 used a nonbiocompatible membrane. Erythrocyte sedimentationrate was determined, using a modified Westergren method. Plasmafibrinogen concentration, complete blood count, and serum chemistrieswere also studied. RESULTS.: Erythrocyte sedimentation rate was normal or mildly elevatedin most of our patients, with a median of 30 mm/h. Linear analysisfound positive correlation between erythrocyte sedimentationrate and fibrinogen concentration, globulin level, platelet,and white cell counts, and negative correlation with haematocrit.Fibrinogen concentration was normal in 22 patients, and moderatelyelevated in 14. It was significantly higher in diabetic patients,or those using a nonbiocompatible membrane. The same positivecorrelations were found for fibrinogen concentration as forerythrocyte sedimentation rate. CONCLUSIONS.: We conclude that erythrocyte sedimentation rate can be usedin haemodialysis patients much in the same way as in the generalpopulation, as it is influenced by the same factors, and itsbaseline value is lower than previously reported. The lowerconcentration of fibrinogen, an independent predictor of cardiovascularrisk, in patients treated with biocompatible membranes may beof clinical relevance.     

Left Atrial Appendage Outflow Velocity Index is Superior to Conventional Criteria for Prediction of Maintenance of Sinus Rhythm after Cardioversion. An Echocardiographic Study in Patients with Atrial Fibrillation of a Few Months' Duration

Objective - To investigate whether left atrial appendage outflow velocity alone or in relation to left atrial diameter is a superior predictor of sinus rhythm maintenance after cardioversion compared with traditional clinical or echocardiography parameters. Design - Sixty-two patients with their first episode of atrial fibrillation were examined using echocardiography before DC-cardioversion. At one month's follow-up, 42 patients had maintained sinus rhythm (group A), and 20 had relapsed into atrial fibrillation (group B). There were no differences in arrhythmia duration or antiarrhythmic therapy between the groups. Results - Left atrial diameter measured by echocardiography was smaller in group A (42 mm, 95% CI 40.9-44.1 mm) compared with group B (46 mm, 95% CI 43.4-48.2, p &lt; 0.05). Patients in group A had a higher left atrial appendage outflow velocity at 0.44 m/s (95% CI 0.39-0.49) compared with 0.34 m/s (95% CI 0.30-0.37) in group B (p &lt; 0.01). The ratio of left atrial appendage flow to left atrial diameter was 0.011 (95% CI 0.009-0.012) in group A compared with 0.008 (95% CI 0.007-0.009) in group B, and 63% (95% CI 33-78) of the patients in group A had velocity ratio &gt;0.009 compared with 20% (95% CI 2-38) in group B, (p &lt; 0.01). Stepwise multiple logistic regression analysis showed that a velocity ratio &gt;0.009 was the only predictor for maintenance of sinus rhythm one month after cardioversion with an odds ratio of 6.4 (95% CI 1.9-23.8), (p = 0.004). Conclusion - The ratio of left atrial appendage outflow velocity to left atrial diameter is superior to the traditionally used criteria for prediction of maintenance of sinus rhythm following DC-conversion of first-episode atrial fibrillation.     

Concurrent prophylactic left atrial appendage exclusion: results from a randomized controlled trial pilot study

Objective: The left atrial appendage is a significant source of cardioembolic thrombi. Open mitral valve surgery presents an opportune time to exclude this appendage from cardiovascular circulation. However, sparse randomized trial support exists for this concomitant procedure. We therefore designed a randomized controlled trial to assess the short- and long-term outcomes of concomitant left atrial appendage exclusion. This report details early outcomes of the pilot trial. Methods: Forty-three patients were randomized to either undergo concomitant suture exclusion of their left atrial appendage under direct vision or not during their open mitral valve surgery. Clinical and biochemical postoperative outcomes, including hemodynamic and hemostatic parameters, were analyzed. Results: There were no deaths in either group. The incidence of cerebrovascular events, myocardial infarction, respiratory failure, and acute renal injury were similar between groups; a composite outcome of 10 major postoperative complications occurred in 32% of the left atrial appendage exclusion group versus 38% of the control group (p = 0.75). Intensive care (median stay 2 days vs 1 day in the control group, p = 0.55) and hospital lengths of stay (median stay 9 days in both groups, p = 0.98) were also similar between groups. Specifically, no additional hemodynamic alterations (need for intra-aortic balloon pump in 1 vs 2 patients in the control group, p = 0.61) or hemostatic complications (no re-operations for bleeding in either group, need for blood product transfusion in 2 vs 1 patient in the control group, p = 1.0) were noted in the left atrial appendage exclusion group. Conclusions: This pilot trial demonstrates the safety of and feasibility of a larger trial powered to detect clinically relevant short- and long-term outcomes of concomitant left atrial appendage exclusion with open mitral valve surgery.     

高龄冠心病合并心房颤动患者行非体外循环冠状动脉旁路移植术中左心耳处理的回顾性队列研究

目的 本文旨在探讨左室射血分数(LVEF)降低的高龄冠心病合并心房颤动(房颤)患者在非体外循环冠状动脉旁路移植术(OPCABG)中同期处理左心耳的手术技巧及效果评价.方法 纳入2013～ 2018年,84例OPCABGLVEF降低(＜50％)的高龄(年龄≥70岁)冠心病合并房颤患者在我科行非体外循环冠脉搭桥术.男54例...     

Use of Intraoperative Transesophageal Echocardiography to Predict Atrial Fibrillation after Coronary Artery Bypass Grafting

Background: Postoperative atrial fibrillation in coronary artery bypass graft surgery occurs in 10-40% of patients. It is associated with a significant degree of morbidity and results in prolonged lengths of stay in both the intensive care unit and hospital.

Methods: The authors prospectively evaluated patients undergoing coronary artery bypass with detailed transesophageal echocardiography examinations conducted before and after cardiopulmonary bypass to study whether risk factors for atrial fibrillation could be identified. Demographic and surgical parameters were also included in the analysis. Selected variables were subjected to univariate and subsequent multivariate analyses to test for their independent or joint influence on atrial fibrillation.

Results: Seventy-nine patients had assessable transesophageal echocardiography examinations. Significant univariate predictors of atrial fibrillation included advanced age (P = 0.002), pre-cardiopulmonary bypass left atrial appendage area (P = 0.04), and post-cardiopulmonary bypass left upper pulmonary vein systole/diastole velocity ratio (P = 0.03). When these three factors were considered together in a multiple logistic regression analysis, left upper pulmonary vein systole/diastole velocity ratio was a significant predictor (P < 0.05), as was the joint effect of age plus pre-cardiopulmonary bypass left atrial appendage area (P = 0.005). The probability of developing atrial fibrillation for the combination of age = 75 yr, post-cardiopulmonary bypass left upper pulmonary vein systole/diastole velocity ratio = 0.5, and left atrial appendage area = 4.0 cm was 0.83 (95% confidence interval, 0.51-0.96).     

Video-assisted bilateral pulmonary vein isolation and left atrial appendage exclusion for atrial fibrillation

OBJECTIVE: Pulmonary vein isolation is curative in selected patients with atrial fibrillation. The objective of this study was to assess the feasibility and safety (midterm results) of video-assisted thoracoscopic epicardial pulmonary vein isolation. METHODS: Twenty-seven patients (22 male patients) with atrial fibrillation (18 paroxysmal, 4 persistent, and 5 permanent; average age, 57 years) underwent bilateral video-assisted thoracoscopic off-pump epicardial pulmonary vein isolation and exclusion of the left atrial appendage. All patients had had unsuccessful drug therapy or were intolerant to antiarrhythmic drug therapy or were intolerant to warfarin. The approach included two 10-mm ports and one 5-cm working port (non-rib spreading) bilaterally. Pulmonary vein isolation was achieved bilaterally by using a bipolar radiofrequency device. The left atrial appendage was excised with a surgical stapler. RESULTS: Bilateral pulmonary vein isolation and left atrial appendage excision was performed successfully in all patients. There were no conversions to sternotomy or thoracotomy. All patients were extubated in the operating room. Postoperative complications in 3 patients were minor and resolved within 48 hours. One morbidly obese patient had more serious complications related to comorbid conditions. Average postoperative follow-up is approximately 6 months (173.6 days). Twenty-three patients have been followed up for greater than 3 months, and 21 of these patients are free of atrial fibrillation (91.3%). The results of magnetic resonance angiography were normal (no pulmonary vein stenosis) in 12 of 12 patients evaluated 3 to 6 months postoperatively. CONCLUSIONS: Bilateral video-assisted thoracoscopic pulmonary vein isolation with excision of the left atrial appendage is feasible and safe and offers a promising, new, minimally invasive, beating-heart approach for curative surgical treatment of atrial fibrillation.     

Left atrial appendage outflow velocity index is superior to conventional criteria for prediction of maintenance of sinus rhythm after cardioversion. An echocardiographic study in patients with atrial fibrillation of a few months' duration

OBJECTIVE: To investigate whether left atrial appendage outflow velocity alone or in relation to left atrial diameter is a superior predictor of sinus rhythm maintenance after cardioversion compared with traditional clinical or echocardiography parameters. DESIGN: Sixty-two patients with their first episode of atrial fibrillation were examined using echocardiography before DC-cardioversion. At one month's follow-up, 42 patients had maintained sinus rhythm (group A), and 20 had relapsed into atrial fibrillation (group B). There were no differences in arrhythmia duration or antiarrhythmic therapy between the groups. RESULTS: Left atrial diameter measured by echocardiography was smaller in group A (42 mm, 95% CI 40.9-44.1 mm) compared with group B (46 mm, 95% CI 43.4-48.2, p < 0.05). Patients in group A had a higher left atrial appendage outflow velocity at 0.44 m/s (95% CI 0.39-0.49) compared with 0.34 m/s (95% CI 0.30-0.37) in group B (p < 0.01). The ratio of left atrial appendage flow to left atrial diameter was 0.011 (95% CI 0.009-0.012) in group A compared with 0.008 (95% CI 0.007-0.009) in group B, and 63% (95% CI 33-78) of the patients in group A had velocity ratio >0.009 compared with 20% (95% CI 2-38) in group B, (p < 0.01). Stepwise multiple logistic regression analysis showed that a velocity ratio >0.009 was the only predictor for maintenance of sinus rhythm one month after cardioversion with an odds ratio of 6.4 (95% CI 1.9-23.8), (p = 0.004). CONCLUSION: The ratio of left atrial appendage outflow velocity to left atrial diameter is superior to the traditionally used criteria for prediction of maintenance of sinus rhythm following DC-conversion of first-episode atrial fibrillation.     

A modified maze procedure performed only on the left atrium for chronic atrial fibrillation associated with mitral valve disease: Report of a case

We describe herein the successful treatment of a patient with chronic atrial fibrillation (AF) associated with mitral valve stenosis and regurgitation, achieved by performing a modified maze procedure on the left atrium alone. The patient was a 51-year-old man who had suffered from intractable AF for 17 years, causing multiple cerebral emboli and palpitations. He had undergone open mitral commissurotomy and balloon commissurotomy 15 and 7 years ago, respectively. On admission, an echocardiogram revealed mitral valve restenosis and thrombosis in the left atrial appendage. Prosthetic valvular replacement was performed following isolation of all pulmonary veins with cryoablation to the posterior wall of the left atrium and excision of the left atrial appendage. Postoperatively, the AF disappeared and echocardiogram demonstrated a left atrial kick in the mitral valvular inflow without any evidence of thrombosis in the left atrium. Thus, we believe that our modified left side only maze procedure is a simple and efficient method for the treatment of chronic AF with mitral valve disease.     

Use of intraoperative transesophageal echocardiography to predict atrial fibrillation after coronary artery bypass grafting

BACKGROUND: Postoperative atrial fibrillation in coronary artery bypass graft surgery occurs in 10-40% of patients. It is associated with a significant degree of morbidity and results in prolonged lengths of stay in both the intensive care unit and hospital. METHODS: The authors prospectively evaluated patients undergoing coronary artery bypass with detailed transesophageal echocardiography examinations conducted before and after cardiopulmonary bypass to study whether risk factors for atrial fibrillation could be identified. Demographic and surgical parameters were also included in the analysis. Selected variables were subjected to univariate and subsequent multivariate analyses to test for their independent or joint influence on atrial fibrillation. RESULTS: Seventy-nine patients had assessable transesophageal echocardiography examinations. Significant univariate predictors of atrial fibrillation included advanced age (P = 0.002), pre-cardiopulmonary bypass left atrial appendage area (P = 0.04), and post-cardiopulmonary bypass left upper pulmonary vein systole/diastole velocity ratio (P = 0.03). When these three factors were considered together in a multiple logistic regression analysis, left upper pulmonary vein systole/diastole velocity ratio was a significant predictor (P < 0.05), as was the joint effect of age plus pre-cardiopulmonary bypass left atrial appendage area (P = 0.005). The probability of developing atrial fibrillation for the combination of age = 75 yr, post-cardiopulmonary bypass left upper pulmonary vein systole/diastole velocity ratio = 0.5, and left atrial appendage area = 4.0 cm was 0.83 (95% confidence interval, 0.51-0.96). CONCLUSIONS: Early identification of patients at risk for postoperative atrial fibrillation may be feasible using the parameters identified in this study.     

Increased renal allograft thrombosis in CAPD patients

In a retrospective analysis of 202 renal transplant proceduresin the years 1989–1992 we identified an excess of graftslost from primary renovascular thrombosis in patients receivingcontinuous ambulatory peritoneal dialysis (CAPD) compared tohaemodialysis (HD) patients (9 CAPD versus 0 HD, Chi-squared=9.63;P<0.01). All graft losses from thrombosis occurred within16 days of surgery. Possible predisposing causes were identifiedin three patients. Donor age was greater in CAPD patients losingtheir kidneys from thrombosis compared to the overall CAPD group[means (SD) years, 43.0(12.9) versus 29.1(15.8); P=0.01] whereasno significant difference in haematocrit, platelet count, antibodystatus, cyclosporin use, perioperative hypotension, primarydiagnosis, smoking, or diabetes mellitus was found. Data fromthe EDTA registry for 1990–91 show that graft loss fromprimary renovascular thrombosis in UK-treated patients was reportedin 7.1% of CAPD recipients compared with 1.8% in haemodialysis.We suggest that CAPD patients are at greater risk of graft lossfrom renovascular thrombosis than HD patients and may requiremore intensive fluid and anticoagulant treatment in the perioperativeperiod.     

Cerebral haemodynamics in patients with chronic renal failure: effects of haemodialysis

Background. We measured middle cerebral artery (MCA) flow velocity(FV), dynamic pressure autoregulation, and carbon dioxide reactivity(CRCO₂) in patients with chronic renal failure before and afterhaemodialysis using transcranial Doppler ultrasonography. Methods. Twelve patients on long-term haemodialysis were recruited.MCA FV was measured continuously. The transient hyperaemic responsetest was used to assess cerebral autoregulation, and per centchange in FV per kPa change in end-tidal carbon dioxide wascalculated to assess CRCO₂. All measurements were recorded beforeand after haemodialysis. Results. MCA FV (mean [SD]) decreased from 57 (10) cm s^–1before to 46 (13) cm s^–1 after haemodialysis (P<0.01).The transient hyperaemic response ratio (THRR) was (mean [SD])1.29 (0.13) before haemodialysis and did not change significantlyfollowing haemodialysis (1.36 [0.10]). CRCO₂ was 21.7 (8.3)%kPa^–1 before haemodialysis and remained unchanged afterwards(20.9 [3.8]% kPa^–1). Values in normal subjects for MCAFV, THRR and CRCO₂ are 56 (12) cm s^–1, 1.26 (0.13) and22 (6)% kPa^–1, respectively. Conclusions. MCA FV decreases significantly after haemodialysis.Dynamic pressure autoregulation and CRCO₂ remain normal in patientswith chronic renal failure, and are not altered significantlyby haemodialysis. Presented at the European Society of Anaesthesiologists AnnualCongress Amsterdam, May 1999.     

Inverse relationships between haemoglobin and ristocetin-induced platelet aggregation in haemodialysis patients under erythropoietin therapy

BACKGROUND.: Amelioration of the anaemia of chronic renal failure and subsequentimproved haemorheology result in correction of bleeding diathesisas evidenced by shortening of the skin bleeding time (BT). However,the relationship between the haematocrit and platelet-vesselwall interactions in haemodialysis (HD) patients under recombinanthuman erythropoietin (rHuEpo) therapy, assessed by plateletaggregation in response to ristocetin is more complex and somewhatinconsistent. METHODS.: We investigated the relationship between haemoglobin (Hb) levelsand whole blood ristocetininduced platelet aggregation (electricimpedance method) in 28 HD patients treated with rHuEpo, andwith normal BT. The measurements were repeated in 16 subjectsafter having reduced platelet aggregability with orally administeredketanserin. RESULTS.: Ristocetin-induced platelet aggregation in the whole group wascomparable to those found in 21 age-matched healthy subjects(normals) and in 25 HD patients not treated with rHuEpo (uraemics).Interestingly, a significant inverse correlation between thisaggregation and Hb concentration was found (r = –0.392,P<0.05). In the group of 16 patients, the preketanserin aggregationwas more intensive than in the normals and uraemics (P<0.05).Ketanserin produced a fall in ristocetin-induced platelet aggregation(P<0.02), prolongation of the BT (P<0.02) and, unexpectedly,a decrease in serum Epo concentration (P<0.0002) and theHb level (P<0.001). Again, an inverse correlation betweendepressed ristocetin-induced platelet aggregation and loweredHb concentration was found (r= –0.590, P<0.02). Moreover,a strong positive correlation between the extent of preketanserinplatelet aggregation and the decrease in the intensity of thisprocess that followed the trial was observed (r=0.919, P<0.000005).There were no changes in other haematological parameters orarterial blood pressure. CONCLUSIONS.: Considering the role of von Willebrand factor and fibrinogenin mediating ristocetin-induced platelet aggregation, and enhancedsynthesis and/or release of these macromolecules in responseto uraemia or inflammation, we suggest that exaggerated whole-bloodplatelet aggregability to ristocetin points to blunted erythropoiesisin HD patients on rHuEpo therapy.     

Comparison of peritoneal dialysis and haemodialysis after renal transplant failure

Background. A growing number of patients are returning to dialysisafter renal transplant failure. The aim of this study is todetermine whether peritoneal dialysis (PD) is a safe and goodtreatment option for these patients. Methods. All patients returning to PD or haemodialysis (HD)after renal transplant failure before 1 October 2002 at theUniversity Hospital Gasthuisberg, Leuven, Belgium, were evaluated.Data were collected until death, retransplantation (reTx), transferto HD or PD or until 1 January 2003. Results. Twenty-one patients starting PD (PDpostTx-group) and39 patients starting HD (HDpostTx-group) after renal transplantfailure were included in the study. There were no significantdifferences in age, sex, serum albumin- and CRP-levels at baseline.The total time on renal replacement therapy at transplant failureand time to transplant failure did not differ between the twogroups either. Furthermore, the baseline comorbidity was similarin both groups. During follow-up, the outcome did not differsignificantly between the two groups. However, there was a tendencytowards higher patient survival and reTx tended to be more frequentin the PDpostTx-group. Moreover, patients in the HDpostTx-grouptended to accrue more new comorbidity. The incidence of peritonitisand the evolution of dialysis adequacy (renal and peritonealKt/V and creatinine clearances) with time in the PDpostTx-groupwas similar to that seen in our centre's PD patients who hadnever undergone transplantation before. Conclusions. This study suggests that the outcome in patientsstarting PD after renal transplant failure is at least as goodas the outcome in those starting HD. Although these observationalfindings warrant further confirmation, PD therefore can be regardedas a safe and good treatment option for patients returning todialysis after renal transplant failure.     

Haemodynamic changes induced by the correction of anaemia by erythropoietin: role of antiplatelet therapy

BACKGROUND.: In a restrospective study, antiplatelet therapy has been shownto be associated with a decreased incidence of erythropoietin-inducedhypertension. In order to ascertain the role of antiplateletdrugs in the haemodynamic response to the correction of anaemiaby rHuEpo, 18 patients on chronic haemodialysis who startedrHuEpo therapy were prospectively studied. METHODS.: The subjects were randomly assigned to receive or not, one ofthe following antiplatelet drugs: ditazole (3 patients), ticlopidine(3 patients) or aspirin plus dipyridamole (3 patients). Cardiacindex (CI) by echo-Doppler, total peripheral resistance (TPR)and mean arterial pressure (MAP) were determined at baseline10 and 20 weeks following the initiation of rHuEpo therapy.rHuEpo therapy was administered subcutaneously at the same dose(40 U/kg thrice weekly) during the first 10 weeks. Ten uraemicpatients on haemodialysis who had never received rHuEpo therapyserved as the control group. RESULTS.: One patient in the group without antiplatelet drugs discontinuedthe study due to the development of severe hypertension after12 weeks on rHuEpo therapy. There were no significant differencesin the haemodynamic parameters at baseline. At 10 weeks, MAPwas higher in patients without than with antiplatelet drugsor controls untreated with rHuEpo (128.5 ± 28 versus100.6 ± 13.5 versus 98.7 ± 14 mmHg respectively,P = 0.0047), TPR was also higher in patients without antiplateletdrugs than in the 2 other groups (1919 ± 433 versus 1576± 359 versus 1418 ± 324 din.seg.cm^–5 m²respectively, P = 0.0231), but CI did not differ among the threegroups. At 20 weeks, MAP was still higher in patients withoutantiplatelet drugs than in patients with antiplatelet drugsor controls not on rHuEpo therapy respectively (112.9 ±24.6 versus 91.0 ± 9.0 versus 101.7 ± 14.1 mmHgrespectively, P = 0.075), but at this stage TPR and Cl did notdiffer among the three groups. CONCLUSIONS.: These data reinforce the previous observation that antiplatelettherapy may prevent the development of rHuEpo-induced hypertension.     

Preventing Graft Thrombosis After Renal Transplantation: A Multicenter Survey of Clinical Practice

Background

Renal allograft vascular thrombosis is a complication that often results in graft loss. Since there are no guidelines on immediate postoperative thromboprophylaxis, we performed a telephone survey of clinical practice in all renal transplantation centers in France.

Methods

Each center considered 4 cases relating to renal transplant candidates on dialysis with an increasing risk of thrombosis: Case 1: patient with no identified risk factors; Case 2: patient with an earlier incidence of deep vein thrombosis; Case 3: patient with ischemic heart disease on antiplatelet therapy; Case 4: patient with atrial fibrillation taking a vitamin K antagonist (VKA) with lupus nephritis syndrome.

Results

The treatments proposed by the centers (%) were: Case 1: No anticoagulation therapy (57.1%), calcium heparin at prophylactic doses (P-dose) (40%), or unfractionated heparin (UFH); (P-dose; 2.9%). Case 2: No anticoagulation therapy (34.3%), calcium heparin (P-dose; 51.4%), or UFH (P-dose; 5.7%). Case 3: (A) Interruption of aspirin (65.7%), and either no anticoagulation therapy (21.7%) or substitution of aspirin by calcium heparin (P-dose; 56.6%) or by UFH (P-dose; 8.7%). (B) No interruption of aspirin (34.3%), and either no additional prophylaxis (58.3%) or calcium heparin (P-dose; 33.3%). Case 4: Interruption of VKA (100%), and UFH at a curative dose (68.6%), UFH (P-dose; 14.3%), or calcium heparin (P-dose; 11.4%).

Conclusions

Practices varied widely in the absence of studies of sufficiently high power. There is a need for a preoperative classification of thrombotic and hemorrhagic risk among renal transplant candidates and for consensus guidelines.     

Monoclonal gammopathy after intense induction immunosuppression in renal transplant patients

OBJECTIVES.: Incidence and risk factors of post-transplant monoclonal gammopathywere studied in renal transplant patients who received theirgrafts between 1982 and 1992 (n=390 grafts). Immunoelectrophoresiswas performed at annual intervals after transplantation. RESULTS.: Forty-six cases of clonal gammopathy were detected: 35 monoclonal,11 bi- or triclonal, with a predominance of IgG and K light-chainsubtypes (IgG, 39; IgA, 3; IgM, 4; K, 35; , 19). Gammopathywas transient in 17 patients (37%). The 5-year cumulative incidenceof gammopathy was 10.7%, much higher than expected for a groupof similar age from the general population. Thirty of the 46gammopathies appeared within the first 2 years of transplantation.Gammopathy never progressed to multiple myeloma during follow-up(median 1 year; (range 0–10)); one patient subsequentlydeveloped Kaposi sarcoma. The 2-year incidence of gammopathywas much higher in patients transplanted in 1989–1991(23/142) than in 1982–1988 (7/248) (P<0.0001). Thiscoincided with the use of quadruple induction immunosuppression(cyclosporin A+azathioprine+prednisone plus either ATG-Fresenius(ATG-F) or OKT3) since 1989. The risk for acquiring gammopathywithin 2 years of transplantation was 14.7% (95% CI 9.2, 20.3%)in patients receiving quadruple induction therapy, but only3.0% (CI 1.2, 6.1%) without such therapy (P<0.0001). Therisk for patients receiving quadruple immunosuppression withOKT3 was 24.5%, significantly greater than with ATG-F (11.8%,P<0.05). Discriminant analysis revealed that the type ofimmunosuppression, but not age or year of transplantation, wereindependent risk factors for gammopathy. CONCLUSIONS.: Monoclonal gammopathy frequently occurs after renal transplantation.Risks are higher for patients receiving quadruple inductionimmunosuppression, particularly if it includes OKT3. Follow-upof these patients is warranted for the early detection of malignanttransformation.     

Tandem plasmapheresis and haemodialysis as a safe procedure in 82 patients with immune-mediated disease

Background. A number of medical, mostly immune-mediated conditionscall for a combination therapy consisting of plasmapheresisand haemodialysis. While the two treatments are most commonlyapplied separately, we describe here the technical details ofproviding a combined ‘tandem’ treatment. Method. The components of a dialyzer (polysulfon membrane) andplasma filter are serially connected by a continuous arteriovenoushaemofiltration (CAVH) system. In an extracorporeal circulation,using a blood pump the patient's blood is led first to the plasmafilter and then into the dialyzer. The substituate connectionis located behind the plasma filter and before the dialyzer.At the beginning it is obligatory to carry out an inspectionof tubing system leakages. Afterwards, the system is flushedwith a heparinized (5000 IE) sodium chloride solution that isremoved thereafter. During the treatment, a blood flow of 150–200 ml/min ispossible. In each case, the plasmafiltration and the ultrafiltrationshould not exceed 25% of the blood flow. The whole time, anintermittent check of blood pressure and heart rate is necessary.The total procedure does not take longer than a routine haemodialysis(3–4 h). Results. In 82 patients we performed 483 tandem treatments duringthe last 16 years. None of the patients had volume disturbancescaused by plasma shifts and derangements of electrolytes andacid–base balance were immediately equalized. There wereno episodes of hypotension or bleeding. Back-filtration didnot occur. Conclusion. Providing both haemodialysis and plasmapheresisat the same time reduces treatment time and thus, overall costof the treatment. This retrospective analysis shows the tandemtreatment to be safe and effective.     

The left atrial appendage: our most lethal human attachment! Surgical implications

Objectives: To prevent death from atrial fibrillation, a cardiac disease which kills by producing emboli. Atrial fibrillation causes about 25% of strokes and increases stroke rate by five times. Over 90% of these embolic strokes are from clots originating in the left atrial appendage. This study addresses the surgical feasibility of removing the appendage to prevent future deaths in two subcategories of patients. (1) Prophylactic removal during open-heart surgery to study its safety. Theoretically, as these patients age and some develop atrial fibrillation, protection from embolic strokes would already be present. (2) Therapeutic removal in chronic atrial fibrillation patients by means of a thorascopic approach. Its technical feasibility is demonstrated. Its actual stroke prevention potential awaits large studies. Methods: Appendectomy has been evaluated three ways. (1) Experimentally, thorascopic appendage removal was performed on 20 goats with endoscopic approach. Late studies showed a cleanly healed atrial closure after stapling, and no puckering of tissue as seen with the purse-string approach. (2) Safety of human appendectomy was demonstrated in 437 patients (1995–1997). Routine appendectomy was performed during open-heart surgery. Forty-three appendages were stapled, 391 sutured off. (3) Thorascopic appendectomy in seven patients with chronic atrial fibrillation has been successfully accomplished as an isolated surgical procedure. Stapling or suture closure provides a much cleaner, non-puckered suture line than a purse string. Results: In prophylactic removal, no acute bleeding occurred. No late problems have been identified. Endoscopic removal of the appendage has been successful in seven atrial fibrillation patients. Conclusions: The left atrial appendage is a lethal source of emboli in atrial fibrillation patients. As patients age and often develop atrial fibrillation, prophylactic appendage removal whenever the chest is open is suggested as a method to prevent future strokes. In chronic atrial fibrillation patients, appendectomy can be done with a mini-thorascopic approach. Further studies are planned to demonstrate the effectiveness of appendectomy in preventing strokes in the chronic fibrillating patients.