Polidocanol (Lauromacrogol 400) has anti-angiogenic effects in vitro and in vivo.

OBJECTIVE: Polidocanol is the most frequently used sclerosant for sclerotherapy all around the world. Our experimental research aims to find out the angiogenic effects of Polidocanol. MATERIALS AND METHODS: Angiogenic activity of polidocanol was examined in vivo in the chick chorioallantoic membrane (CAM) model, cell viability assay (human umbilical vein endothelial cells - HUVECs) and in vitro tube formation assay of HUVECs. RESULTS: In CAM assay, a significant decrease on CAM vessel growth was observed after the application of polidocanol solutions. Vessel growth inhibition was strongly dose-dependent. There was a cytotoxic effect on HUVECs in the presence of polidocanol observed with MTT assay (p < 0.05). In the tube formation assay, statistically significant decrease in tube formation was observed in polidocanol group. It was found that polidocanol had an anti-angiogenic effect (p < 0.05). The results provide evidence that polidocanol decreases angiogenesis and has a cytotoxic effect on ECs. CONCLUSIONS: These results provide evidence that Polidocanol (lauromacrogol 400) have strong anti-angiogenic effects in vitro and in vivo. Further researches needed to reveal early and long-term effects of polidocanol in the human vascular system and new treatment approach as an anti-angiogenic therapy.

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.

In vitro effect of sodium nitrite on platelet aggregation in human platelet rich plasma--preliminary report.

OBJECTIVE: The role of nitrates and nitric oxide on platelet functions has obtained an increasing attention with respect to their potential effects on cardiovascular disorders. In this study we aimed to analyze the effect of sodium nitrite on platelet functions in human platelets. PATIENTS AND METHODS: This in vitro study was designed to show the effect of sodium nitrite on platelet functions in seven healthy volunteers. Blood samples were centrifuged to prepare platelet rich plasma and platelet poor plasma. Platelet rich plasma was diluted with the platelet poor plasma to have a final count of 300,000 ± 25,000 platelets. Platelet rich plasma was incubated with six different increasing doses (from 10 µM to 5 mM) of sodium nitrite for 1 hour at 37°C. Then stimulating agents including collagen (3 µg ml-1), adenosine diphosphate (10 µM), and epinephrine (10 µM) were added to the cuvette. Changes in light transmission were observed for 10 minutes. In addition spontaneous aggregation were performed in control group with all aggregating agents separately. RESULTS: Effect of sodium nitrite on agonist-induced platelet aggregation depends on the concentration of sodium nitrite. Compared with control group, agonist-induced platelet aggregations were significantly suppressed by sodium nitrite at the concentration of 5, 1.0 and 0.5 mM. CONCLUSIONS: Our results suggested that sodium nitrite has inhibitory effects in vitro on platelet aggregation in a dose-dependent manner.

Comparison of angiogenic and proliferative effects of three commonly used agents for pulmonary artery hypertension (sildenafil, iloprost, bosentan): is angiogenesis always beneficial?

OBJECTIVE: Pulmonary artery hypertension (PAH) is devastating disease that has very serious outcomes. Dysregulated angiogenesis is one of the main responsible courses in pathophysiology of disease. Our experimental research intends to find out and compare the angiogenic effects of medications used sildenafil, iloprost, and bosentan in the treatment of PAH. MATERIALS AND METHODS: This study was performed in Department of Biochemistry and Cancer and Stem Cell Research Laboratory of our institutes between August and October 2014. Angiogenic activity of sildenafil, iloprost, and bosentan were examined in vivo in chick chorioallantoic membrane (CAM) model and in vitro tube formation assay of human umbilical vein endothelial cells (HUVECs). Proliferative activity of these three agents was also determined through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on HUVECs. RESULTS: In CAM assay, when compared to the control and drug groups, treatment with sildenafil solutions resulted in a significant dose-dependent increase (budding, sprouting, extravasation) on CAM vessel growth. While there was no significant proliferative effect with iloprost and bosentan, presence of sildenafil caused a statistically significant proliferation on HUVECs following 24 and 48 h incubation (p < 0.05) compared to the control group. Comparing the tube length/area ratio values, there was statistically significant increase in sildenafil group with respect to the other 2 groups (p < 0.05). Iloprost and bosentan did not show a significant effect. CONCLUSIONS: The results provide evidence that sildenafil but not iloprost and bosentan induces angiogenesis in vitro and in vivo. Dysregulated angiogenesis, as an important pathophysiological part in the progression of PAH, may be triggered by the chronic ingestion of sildenafil in the long treatment period and may cause negative effects.

Acute high dose-fentanyl exposure produces hyperalgesia and tactile allodynia after coronary artery bypass surgery.

OBJECTIVE: Opioid-induced hyperalgesia is well known complication of acute high dose and chronic opioid therapy. In this study, we evaluated development of opioid-induced hyperalgesia following intraoperative short-term use of µ-opioid agonist fentanyl after coronary artery bypass surgery. PATIENTS AND METHODS: 100 patients undergoing elective coronary artery bypass graft surgery is divided into two groups. In group I (low dose), anesthesia was induced with propofol 1-2.5 mg/kg and fentanyl 2 mcg/kg, in group II (high dose) fentanyl 40-70 mcg/kg was used. In group I, propofol 5-10 mg/kg/h, fentanyl 1-3 mcg/kg/h, in group II fentanyl 5-10 mcg/kg/h was used for maintenance of anesthesia. The tactile and thermal thresholds were measured before surgery and in 1st, 3rd and 7th postoperative days by using Von Frey filaments and a thermal source, respectively. RESULTS: Tactile thresholds were significantly decreased at the first (6,08±0.21 and 3.76±0.13 g; p<0.001) and third (6.76±0.24 and 4.96±0.16 g; p<0.001) postoperative days compared to baseline preoperative values (7.72±0.26, and 7.60±0.21 g; p=816) in two groups. Postoperative 1st (13.45±0.33 and 10.05±0.24 sec; p<0.001) and 3rd day (14.77±0.28 and 13.17±0.26 sec; p<0.001) assessments showed a statistically significant thermal hyperalgesia compared to the preoperative baseline values (16.67±0.51 and 16.45±0.42 sec; p=0.997) in two groups. This decrease in both tactile and thermal thresholds returned to baseline control values at the 7th day of measurement. CONCLUSIONS: Our results showed that patients undergoing coronary artery bypass surgery receiving fentanyl anesthesia developed postoperative tactile allodynia and thermal hyperalgesia and this was more prominent in high dose group.

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.

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.

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.