New probing and warm-wash-out technique improves early patency rates in arteriovenous fistula surgery.

OBJECTIVE: Arteriovenous fistulas (AVFs) are commonly used during hemodialysis. Early failure of AVFs is quite common with incidence of 43% to 63%. In this study we aimed to describe a novel approach to AVF surgery for improving early patency rates. PATIENTS AND METHODS: Patients were divided into two groups according to use of probing and warm-wash-out technique. Group I consisted of 31 patients with additional probing technique. Group II consisted of 32 patients without additional maneuver. End-to-side anastomosis were used to all patients. Technical success was defined as having palpation of a thrill on fistula. Flow rates of draining vein was measured at 1st hour, 24th hour, 1st week and 3rd week of surgery. SURGICAL TECHNIQUE: Classical maneuvers were performed until end of the anastomosis. At this time, vein lumen was washed by low-dosed heparinized warm fluid, with assistance of a simple catheter. RESULTS: Technical success was similar in both groups at 1st hour and 24th hour, while there were significantly differences between groups at 1st week (p = 0.042) and 3rd week (p = 0.05) assessments. Flow rates were also measured significantly higher in Group I at 1st hour (p = 0.011) and 24th hour (p = 0.016). Flow rates were almost similar in two groups at 1st and 3rd weeks but overall success rate was higher in Group I comparing with Group II (96.8% vs. 81.3%, respectively, p = 0.05). CONCLUSIONS: Probing and warm-wash out technique will simply increase the surgical success and flow rate of draining vein.

Effects of taurine on contractions of human internal mammary artery: a potassium channel opening action.

OBJECTIVE: Taurine is an abundant amino acid that is widely distributed in human and animal tissues. Pharmacodynamic studies show that taurine has hypotensive and myocardial protective effects. Studies in isolated tissue baths show that taurine relaxes precontracted arteries. This study aimed to show the effects of taurine on human internal mammary artery (IMA) in vitro and to explain the mechanisms of its effects. METHODS: The response in the IMA was recorded isometrically by a force displacement transducer in isolated organ baths. Taurine (20, 40, 80 mM) was added to organ baths after precontraction with KCl (45 mM) or serotonin (5-HT, 30 µM). Taurine-induced relaxations were also tested in the presence of the cyclooxygenase inhibitor indomethacin (10 µM), the nitric oxide synthase inhibitor L-NAME (100 µM), the large conductance Ca2+-activated K+ channel inhibitor tetraethylammonium (TEA, 1 mM), the ATP-sensitive K+ channel inhibitor glibenclamide (GLI, 10 µM), the voltage-sensitive K+ channel inhibitor 4-aminopyridine (4-AP, 1 mM) and the inward rectifier K+ channel inhibitor barium chloride (BaCl2, 30 µM). RESULTS: Taurine did not affect the resting tone of IMA. However, it produced relaxation in the 5-HT and KCl -precontracted preparations. The relaxation to IMA was not affected by GLI, 4-AP, BaCl2, indomethacin and L-NAME. But, TEA inhibited taurine -induced relaxations significantly (p < 0.05). CONCLUSIONS: The preincubation of IMA with taurine antagonized KCl and 5-HT induced contractions in a concentration dependent manner, while it did not affect the resting tone. The relaxations to taurine were significantly antagonized by pretreatment with TEA. These results suggest that mechanism of vasodilator effect of taurine in IMA may be the activation of large conductance Ca2+-activated K+ channels.

Local sympathetic stimulation not only have local effects in patients with Raynaud's phenomenon.

OBJECTIVE: Many other organs and system can be affected in the course of Primary Raynaud's Phenomenon (RP). Simultaneously increased vasospasm in the pulmonary vascular bed may likely affect the pulmonary function. Therefore, we investigated the effect of Raynaud's phenomenon on the respiratory functions in this study. PATIENTS AND METHODS: Between March 2014 and December 2014, 30 patients with the diagnosis of PRP more than two years and 32 age-sex matched healthy controls were enrolled into this study. Cold stimulation test (CST) was performed. Pulmonary function test were performed following 30 minutes after CST and spirometric measurements were calculated. RESULTS: There were no statistically significant differences between two groups regarding their demographic and clinical data. Mean duration of symptoms from onset to present was 3.01 ± 1.05 years. Patients with Primary RP had significantly lower FVC and higher FEV1/FVC values compared to the control groups (p = 0.015 and p=0.045, respectively). CONCLUSIONS: We found that statistically significant decrease of FVC values in patients with Primary RP compared to the healthy controls could be a impaired innervation of pulmonary system and a predictor of pulmonary vasospasm and/or pulmonary Raynaud's phenomenon, which may develop in future periods.

Impact of the intensity of microemboli on neurocognitive outcome following cardiopulmonary bypass.

BACKGROUND: This study aimed to determine whether there was any association between the intensity of intraoperative gaseous microembolic signals (GME), neuropsychological testing and clinical outcome in high-risk patients undergoing coronary artery surgery (CABG). METHODS: Over a 6-month period, GME activity was monitored in 102 Euroscore 6+ patients during cardiopulmonary bypass (CPB) with a conventional 32-micron arterial filter by non-invasive, real-time ultrasonic device. Cognitive tests; line bisection, the Stroop test, finger tapping, and the Rey Auditory Verbal Learning Test were performed at baseline, postoperative one week and postoperative one month. RESULTS: The distribution of GME activity showed that there were three groups of patients: >500 total emboli (n = 38); 250 to 500 emboli (n = 30) and <250 emboli (n = 34) at a detection level of 2% of the circuit diameter on the arterial side. Line bisection, the Stroop test and finger tapping were impaired significantly in >500 emboli patients versus control (<250 emboli) in postoperative week one, but resolved in one month. CONCLUSIONS: Correlation between intraoperative GME intensity and neurocognitive tests suggests that the level of GME might have a role in determining the psychological outcome after CABG with CPB.

Can cardiac surgery be performed safely on patients with haematological malignancies.

INTRODUCTION: Surgical strategy in patients with haematological malignancies must be planned and carried out with the specific aim of decreasing postoperative complications. The aim of this study was to present our experience on patients previously diagnosed with haematological malignancies who subsequently underwent cardiac surgery. We include data to assist other surgeons predict factors affecting postoperative morbidity and mortality in this group of patients. METHODS: Fifteen patients diagnosed with haematological malignancies who had cardiac surgery were retrospectively analysed. Eight patients had chronic lymphocytic leukaemia, six had non-Hodgkin's lymphoma and the rest had chronic myelocytic leukaemia. Coronary artery bypass graft surgery was performed on all of them. RESULTS: There were no hospital mortalities. The average follow-up period was 35 ± 11 (23-56) months. Three patients required early postoperative re-operation because of excessive bleeding. No mortalities were seen in the early postoperative period. There were five (33%) deaths during the late follow-up period. Three patients were lost due to intracranial bleeding (confirmed by autopsy) in the 16th, 23rd and 38th months after surgery. The remaining two patients had sudden death in the eighth and 55th months from nondetectable causes. CONCLUSION: Cardiac surgery can be performed with acceptable early postoperative outcomes in patients with haematological malignancies. Intracranial bleeding is an important factor contributing to late mortality and patient selection and risk stratification are crucial to improving surgical benefits.

A rare complication after coronary artery bypass graft surgery: Ogilvie's syndrome.

Gastrointestinal (GI) complications occur in less than 2% of patients undergoing open-heart surgery. Acute colonic pseudo-obstruction, known as Ogilvie's syndrome, is also a rare complication encountered in 0.046% of patients undergoing coronary artery bypass graft surgery. It is characterised by massive colonic dilatation without mechanical obstruction in patients with underlying medical or surgical conditions. In this report we describe a patient who suffered from acute renal failure requiring haemodialysis, and subsequently Ogilvie's syndrome, which was treated with high-dose neostigmine.

Does puncture site affect the rate of nerve injuries following endovenous laser ablation of the small saphenous veins?

OBJECTIVES: The small saphenous vein (SSV) lies in close relationship with sural nerve and is at risk of damage during surgery or vein ablation procedures on this vein. The aim of this study was to compare the effect of puncture site for SSV endovenous laser ablation (EVLA) on the rate of post-operative sural nerve injury. DESIGN: Randomised controlled study. PATIENTS AND METHODS: Sixty patients with isolated SSV varicose veins (68 limbs) were randomised into two groups. All patients were treated with endovenous laser ablation procedures using radial fibres and a 1470 nm diode laser. In Group 1, SSVs were canulated from lateral malleolar part of the SSV. In Group 2, SSVs were canulated in the mid-calf. EVLA procedures were performed by using 12 W energy and 70 J cm⁻¹ LEED (linear endovenous energy density). Local pain, ecchymosis, induration and paraesthesia in treated regions, vein diameter, treated vein length, tumescent anaesthesia volume, delivered energy were recorded. Follow-up visits were arranged on the 2nd post-operative day, 7th day, 1st, 2nd, 3rd and 6th months. RESULTS: The mean SSV diameters at sapheno-popliteal junction (SPJ) and calf levels were Group 1 SPJ: 6.6 S.D. 1.2 mm, Calf: 5.1 S.D. 1.1 mm, and Group 2 SPJ: 6.8 S.D. 1.6 mm, Calf: 4.9 S.D. 1.3 mm. Adverse events after treatment were 1 patient with induration, 3 with ecchymosis and 6 minimal paraesthesia in Group 1 (malleolar) and 1 local pain, 4 minimal ecchymosis or induration and 1 paraesthesia in Group 2 (mid-calf). In Group 1 in two patients the paraesthesia lasted 2 months and then resolved spontaneously. In the remaining four patients' paraesthesia resolved in less than 1 month without treatment. In Group 2 paraesthesia resolved spontaneously in two weeks. Induration, ecchymosis and local pain also resolved in less than 2 weeks in both groups. There was no recanalisation or reflux in the treated SSV of either group during the follow-up period. CONCLUSION: Treatment of the SSV by endovenous laser ablation using a 1470 nm laser and a radial fibre is safe and effective. Puncturing the vein at mid-calf level causes less post-operative nerve injury without affecting the recanalisation rates.

Comparison of 980 nm laser and bare-tip fibre with 1470 nm laser and radial fibre in the treatment of great saphenous vein varicosities: a prospective randomised clinical trial.

OBJECTIVES: The aim of this study is to compare efficacy, early postoperative morbidity and patient comfort of two laser wavelengths and fibre types in treatment of great saphenous vein (GSV) incompetence resulting in varicosities of the lower limb. DESIGN: Prospective randomised clinical trial. MATERIALS AND METHODS: Sixty patients (106 limbs) were randomised into two groups. They were treated with bare-tip fibres and a 980 nm laser in group 1 and radial fibres and 1470 nm laser in group 2 in order to ablate the GSV. Local pain, ecchymosis, induration and paraesthesia in treated regions, distance from skin, vein diameter, treated vein length, tumescent anaesthesia volume, delivered energy and patient satisfaction were recorded. Follow-up visits were planned on the 2nd postoperative day, 7th day, 1st, 2nd, 3rd and 6th months. RESULTS: Mean GSV diameters at saphenofemoral junction and knee levels were 12.1 S.D. 4.3 mm and 8.2 S.D. 2.4 mm, and 11.8 S.D. 4.1 mm and 7.9 S.D. 2.6 mm respectively in groups 1 and 2. There were 14 patients with induration, 13 with ecchymosis and nine minimal paraesthesia in group 1 and no or minimal local pain, minimum ecchymosis or induration in group 2. Duration of pain and need for analgesia was also lower in group 2 (p < 0.05). There was significant difference on postoperative day 2, day 7 and 1st month control in favour of group 2 in venous clinical severity scores (VCSS). CONCLUSION: Treatment of the GSV by endovenous laser ablation using a 1470 nm laser and a radial fibre resulted in less postoperative pain and better VCSS scores in the first month than treatment with a 980 nm laser and a bare-tip fibre.

Importance of urinary measurement of glutathione S-transferase in renal dysfunction patients after on- and off-pump coronary artery bypass surgery.

BACKGROUND: Acute renal failure (ARF) occurring after on-pump and off-pump cardiac surgery was assessed by urinary alpha glutathione S-transferase measurement (alpha-GST) in patients who already had renal dysfunction. METHODS: Fifty-one patients with plasma creatinine levels ranging between 1.5 and 2.0 mg/dL were included in the study. On-pump coronary artery bypass was performed in 25 of them, and off-pump surgery in the other 25 patients. Urinary alpha-GST levels, plasma creatinine levels, creatinine clearance and fractional excretion of sodium were measured. RESULTS: Urinary alpha-GST levels were found to be significantly increased at 24 hours postoperatively. A weak correlation was detected between alpha-GST levels and plasma creatinine, creatinine clearance and fractional excretion of sodium. Preoperative and postoperative 24 hour levels showed a positive predictive value for the occurrence of acute renal failure. CONCLUSIONS: Tubular damage produced by cardiopulmonary bypass is not the only factor associated with postoperative ARF. Because factors independent of pump usage can adversely affect renal function, excluding pump usage alone is not sufficient to prevent postoperative ARF in patients who have preoperative renal dysfunction.

Pre-emptive stellate ganglion block increases the patency of radial artery grafts in coronary artery bypass surgery.

BACKGROUND: We evaluated the role of pre-emptive stellate ganglion block (SGB) in preventing radial artery spasm and increasing radial artery graft patency in patients undergoing off-pump coronary artery bypass surgery. METHODS: In this prospective randomized study, 100 patients were divided into two equal groups (n= 50). In group A, SGB was achieved using 10 ml of ropivacaine and, in group B, SGB was not performed. Radial artery blood flow was measured pre- and intra-operatively. Post-operative clinical determinants (S-T segment elevation, use of inotropic agents, incidence of atrial fibrillation) were recorded. Early coronary angiography was performed. RESULTS: According to blood flowmeter measurements, the radial artery blood flow was significantly increased in patients with SGB. The incidence of atrial fibrillation, the need for inotropic agents and S-T segment elevation were all decreased in the SGB group. Angiographic intervention revealed that the incidence of graft spasm was also lower in the SGB group. CONCLUSION: Pre-emptive SGB is an effective method for increasing radial artery blood flow and preventing radial artery spasm. Complications related to radial artery spasm may be decreased and patients may have a more comfortable post-operative period with this method.

Leukodepletion improves renal function in patients with renal dysfunction undergoing on-pump coronary bypass surgery: a prospective randomized study.

BACKGROUND: We aimed to show the impact of leukodepletion on renal function in patients undergoing on-pump coronary revascularization. PATIENTS AND METHODS: Fifty patients awaiting elective on-pump coronary revascularization with normal preoperative cardiac functions and with plasma creatinine levels ranging between 1.5 and 2.0 mg/dL were prospectively randomized into two groups: on-pump CABG with (group A: n = 25) and without leukodepletion (group B, n = 25). Renal glomerular and tubular injury were assessed by urinary alpha glutathione s-transferase (GST), plasma creatinine, and blood urea nitrogen (BUN) levels. RESULTS: The patients consisted of 14 females and 36 males with a mean age of 57.6 +/- 5.3 years. In the leukodepletion group, the mean levels of creatinine, BUN and urinary GST were found to be decreased on the first, third and fifth postoperative days compared with the control group. There was no mortality. Three patients in the control group needed postoperative dialysis. CONCLUSION: Patients with renal dysfunction undergoing on-pump CABG surgery seem to benefit from leukodepletion as a measure to prevent tubular damage and renal impairment compared with a control group.

Comparison of ultrasonically activated scalpel and traditional technique in radial artery harvesting: clinical research.

BACKGROUND: Use of the radial artery (RA) as a conduit in coronary artery bypass grafting (CABG) has become increasingly popular in recent years. The aim of this study was to compare the results of two different RA harvesting techniques. Use of the harmonic scalpel is suggested to be safe and additionally reduces spasm rates. MATERIAL AND METHODS: From January 2000, the first 200 consecutive patients who underwent RA harvesting for CABG were enrolled in this study. Patients were divided into two groups. RA was harvested by means of electrocautery + hemoclips in Group I and by harmonic scalpel + hemoclips in Group II. 30 patients (30 %) in Group I and 25 patients (25 %) in Group II were female. Mean age was 53.9 +/- 9.3 and 53.5 +/- 8.4 years in Group I and Group II, respectively. Hand circulation and ulnar collateral flow was assured with a modified Allen test in all patients preoperatively. During the operation perfusion of the hand was monitored by oximetric plethysmography. The distal end of RA was also explored and clamped with a soft vascular clamp to evaluate the saturation values in the groups. During the clamping period, oxygen saturation values did not decrease so we harvested RAs in all patients. RESULTS: There were no statistically significant differences between the groups with the exception of the RA harvesting times, the postoperative analgesia requirements, the rate of vasospasm and the need for hemostatic clips. CONCLUSION: Harmonic scalpel usage in RA harvesting causes less trauma to adjacent tissues; the analgesia requirements, the rate of vasospasm, the RA harvesting time and the need of hemostatic clips decreases. We conclude that the use of a harmonic scalpel for radial artery harvesting is safer and faster than the routine technique.

Results of endocardial radiofrequency ablation of atrial fibrillation during mitral valve surgery.

AIM: The aim of the study is to evaluate the efficacy of thermocontrolled endocardial radiofrequency (RF) ablation for the patients with mitral valve disorder and associated chronic atrial fibrillation during mitral valve replacement operation. METHODS: Between February 2002 and January 2004, 43 patients with mitral valve disease and associated chronic atrial fibrillation underwent mitral valve replacement and thermocontrolled endocardial RF ablation with Cobra RF system flexible probe at Gulhane Military Academy of Medicine, Department of Cardiovascular Surgery. Eighteen of the patients (41.8%) were males, while the remaining 25 (58.2%) were females. The average age of the patients was 44+/-14.21 (18-66) years. Functional capacity of the patients was class II in 15 (34. 9%), class III in 24 (55.8%), class IV in 4 (9.3%) according to the NYHA classification. At the preoperative period all of the patients were evaluated routinely by twelve-lead ECG, chest film and transthoracic echocardiography (TTE). For the patients over 40 years of age, we performed additional coronary angiography to delineate any coronary lesions. The patients were evaluated at months 1, 3, 6 and annually by twelve-lead ECG, TTE and holter monitoring after discharge. RESULTS: There were not any complications related to the performed technique. No operative and hospital mortality were recorded. At the follow-up period for 35 of 43 patients (81.4%) sinus rhythm was restored. The mean follow-up time was 24.3+/-11.2 (12-35) months. CONCLUSION: Endocardial RF ablation especially during mitral valve surgery is a simple technique to be performed. Early and midterm results of the cohort are satisfying.

A randomized trial of intravenous iloprost (a stable prostacyclin analogue) versus lumbar sympathectomy in the management of Buerger's disease.

AIM: The aim of this study was to compare the effects of iloprost and lumbar sympathectomy (LS) in the treatment of Buerger's disease. METHODS: Two hundred patients with rest pain and/or ischemic ulcers were randomized to undergo LS or 28-day intravenous treatment of iloprost. The primary endpoint was complete healing without pain or major amputation at 4 and 24 weeks. The secondary endpoints were analgesic requirement, reduction in the ulcer size, 50% reduction of the ulcer, and shift in the modified SVS/ISCVS clinical status grading scale. RESULTS: The comparison was carried out in 162 patients (iloprost: n=84; LS: n=78). Complete healing rate was 61.9% in the iloprost group, but 41% in the LS group at the 4th week (P=0.012); respective values for the 24th week were 85.3%, 52.3%, P<0.001. Analgesic requirement was lower in the iloprost group at the 4th and 24th weeks (P=0.01, and P=0.098, respectively). The size of the ulcers decreased more in the iloprost group than the LS group (P=0.044 and P=0.035 at 4th and 24th weeks); 50% reduction in the ulcer size in the iloprost group was greater than in the LS group (P=0.001 and P=0.009 at 4th and 24th weeks). SVS/ISCVS grading scale demonstrated a better clinical benefit in patients treated with iloprost (P<0.001 at 4th week, and P<0.001 and at 24th week). CONCLUSIONS: The results of this independent study indicate that using iloprost relieves ischemic symptoms better than LS. In the era of stable prostacyclin analogues, there is no reliable evidence to support the use of LS in Buerger's disease.

Midterm experience with the Sorin Bicarbon heart valve prosthesis for rheumatic disease.

BACKGROUND: In this study, we present a single center experience with Bicarbon bileaflet valve in 307 patients with rheumatic heart disease. METHODS: Between August 1998 and September 2000, 307 patients underwent heart valve replacement using the Bicarbon bileaflet valve (Sorin Biomedica, Saluggia, Italy) with an average age of 47.19+/-13.21 years (range 14 to 80 years), consisting of 147 males and 160 females at Alkan Hospital, Cardiovascular Surgery Department. Aortic valve replacement (AVR) was performed in 77 patients, mitral valve replacement (MVR) in 156 patients and double valve replacement (DVR) in 74 patients. RESULTS: The early mortality rate was 3.3% (10/307) and there was no late mortality. The actuarial survival rate, including hospital mortality, was 96.74+/-1.01% for the whole group, 96.5+/-1.5% for the MVR group, 97.4+/-1.8% for the AVR group and 97.3+/-1.9% for the DVR group at 35 months. One patient had obstructive valve thrombosis with MVR. The 35 months actuarial freedom from valve thrombosis was 99.58+/-0.4% for the whole group. Four patients were reoperated and the 35 months actuarial freedom from reoperation was 98.53+/-0.7% for the whole group, 98.65+/-0.9% for the MVR group, 96.73+/-02% for the DVR group and 100% for the AVR group. No instances of perivalvular leak, hemolysis, endocarditis or embolism were observed during the entire follow-up period. Mean follow-up duration was 16.5+/-7.9 months (ranged 4 to 35 months). CONCLUSION: We have presented our mid-term results with the Sorin Bicarbon bileaflet valve in patients with rheumatic heart disease, which provided good clinical performance combined with meticulous patient care and advanced surgical techniques.

Clinical experience with Sorin Bicarbon valve in patients with tight mitral valve stenosis and elevated pulmonary hypertension (early and mid-term results).

BACKGROUND: The results of mitral valve replacement (MVR) with Sorin mechanical valves in patients who had tight mitral stenosis with high pulmonary artery pressure were reviewed. METHODS: During a period of two years, from August 1998 to May 2000, a mitral valve replacement with a Sorin Bicarbon mechanical valve was performed in 51 patients with a diagnosis of tight mitral stenosis associated with severe pulmonary hypertension (preoperative mean systolic pulmonary artery pressure was 72+/-12 mmHg, range from 60 to 105 mmHg). There were 37 women and 14 men; mean age was 47.2+/-12 years. Forty-eight patients (94.12%) were in NYHA functional class III or IV. All the patients discharged from the hospital were submitted to a clinical follow-up program. A 100% follow-up was obtained with a mean of 12.6+/-6.4 months (range 2 to25 months). RESULTS: Operative mortality was 3.9%, 2 patients who had concomitant CABG died due to low cardiac output. Twelve patients (23.5%) needed an inotropic pharmacological support during the postoperative time. In one patient a re-exploration for bleeding was necessary, and in another one a cerebrovascular accident occurred 3 days after the operation. After 6 months, one patient was reoperated on because of mechanical valve dysfunction due to pannus formation. All survivors underwent a postoperative echocardiographic assessment. The systolic PAP decreased from a mean preoperative value of 72+/-12 mmHg to 39.9+/-12 mmHg. NYHA functional status significantly improved and 86% of the patients were in NYHA functional class I or II. CONCLUSIONS: The mitral valve replacement with Bicarbon mechanical valve prosthesis shows excellent results in patients with mitral valve stenosis associated with a severe pulmonary hypertension.

Primary pulmonary hypertension and coronary artery bypass surgery.

Coronary artery bypass surgery in patients with primary pulmonary hypertension is extremely rare. Right ventricular failure due to persistent elevation of pulmonary pressure is the most important complication in the postoperative period. Creation of an interatrial septal defect and reducing postoperative supraventricular arrhythmia by amiadarone infusion and continuous nasal oxygen therapy can reduce postoperative mortality and morbidity.

Double coronary endarterectomy on the beating heart in two patients with porcelain aorta.

Patients with porcelain aorta carry a high risk of systemic embolism during coronary artery bypass grafting. Avoiding manipulation of the aorta during operation using the beating heart approach can prevent atheroemboli. In patients with diffuse atherosclerotic coronary artery disease who require endarterectomy, coronary bypass operations can be done safely on the beating heart.

Simple de-airing technique for aortic valve replacement with upper ministernotomy.

Upper ministernotomy for aortic valve replacement is intimidating for many surgeons, not only for limited surgical exposure but also for the inability to complete de-airing the apex of the heart. Conversion to full sternotomy had been reported for this inability to de-air the apex of the heart in a limited number of cases. We describe a simple de-airing method by introducing a 16 GA catheter into the apex of the left ventricle through the aorta and prosthetic valve.

The role of prothrombotic mutations in patients with Buerger's disease.

Thromboangiitis obliterans (TAO), or Buerger's disease, is a segmental occlusive inflammatory disorder of the arteries and veins, and etiopathogenesis is still obscure. In the present study we investigated the prevalence of prothrombin 20210 G-->A, factor V 1691 G-->A (Factor V Leiden), and factor V 4070 A-->G (His 1299 Arg) mutations, found to be associated with increased risk for vascular thrombosis, in 36 patients with TAO. We performed a case-control study of these mutations. The odds ratio for prothrombin 20210 A allele compared with G allele was 7.98 (95% confidence intervals 2. 45-25.93). Only this prothrombotic genetic factor was associated with the risk of TAO (p=0.032). In conclusion, carrying the prothrombin 20210 G-->A may be an important prothrombotic risk factor of TAO. This genetic predisposition must be screened in these patients routinely, and clinical importance must be supported by further investigations.