Abstract: Objective To compare the effects of nitroglycerine (NTG)， Verapamil(VP), papaverine(PA) and the mixed solution of Verapamil and nitroglycerine (VG) on relaxing function of human radial arteries. Methods The radial arteries of thirty patients were used during the operation of coronary artery bypass grafting (CABG). A short segment (1.0-1.5cm) of radial arteris were taken from the distal end of radial arteries of each patient and were cut into vascular rings, which were mounted in the organ bath chamber and then subject to a series of tests for vascular smooth muscle viability and endothelial integrity. The effects of five storage solutions on the relaxing function were evaluated by “OrganBath” technique. The five solutions included: (1) Ringer’ s solution (control group); (2) VP solution (VP group); (3) NTG solution (NTG group); (4) PA solution (PA group); (5) VG solution (VG group). First, challenged with phenylephrine (10-5mol/L), vasorelaxant effect of these drugs (effect onset and efficacy) was observed at different time point and resting tension was recorded. Second, after 30min preincubation with either verapamil, papaverine, phenoxybenzamine or VG mixture, potassium chloride (final concentration of 60mmol/L) was added in the organ bath chamber and then vasoconstriction was observed subsequently. Finally, after 30min pretreatment of different antispasmodic agent in the same way as described above, the vascular rings were mounted in organ bath chamber and challenged with phenylephrine(10-5mol/L). Vascular spasticity and vosospasm duration were observed at different time point which might provide guidance for optimal timing of clinical application. Results The radial arteries in VG, VP, NTG and PA solutions were relaxed in 11 min after vasospasm and there was no difference between them (Pgt;0.05). But during the initial three minutes，the relaxation effect of VG and NTG was significantly better than other two groups. Relaxation curve showed that the ability of vasodilatation of VG, NTG, VP and PA decreased in order. In the experiment about antivasospasm pretreatment of radial arteries, there was no difference between VG and VP group (Pgt;0.05 ), whose effects were better than NTG and PA group(Plt;0.05 ). After cold storage for 24h, VG and VP still could prevent vasospasm. But NTG and PA hardly had any function and there was no difference compared with the control group (Pgt;0.05 ). Conclusion Although in the final all these drugs could prevent and relieve vasospasm of radial arteries in the different level, it appeared that a combination of verapamil and nitroglycenn is more fit for treating radial artery during CABG operation than other drugs.
Objective To compare milrinone （MIN）, Phenoxybenzamine （PHE），and mixture of nitroglycerin and verapamil(NVC) for the prevention and treatment of human radial artery spasm. Methods Residuary radial arteries from 30 patients undergoing coronary artery bypass grafting （CABG） using autologous radial artery from March to September of 2012 in General Hospital of Shenyang Military District were collected. All the artery specimens were cut into 60 vessel rings of 3 mm in width and hanged in the Organ-Bath. Using a random number table，all the vessel rings were divided into 4 groups：PHE group，NVC group，MIN group and blank group （control group）. Firstly，20 vessel rings were used for spasm relaxation experiment with 5 rings in each group. Phenylephrine was added into the Organ-Bath to reach final concentration of 10-3 mol/L in order to cause vessel rings spasm. PHE of 1 mmol/L，NVC of both 30 μmol/L，MIN of 30 μmol/L and Krebs-Ringer’s solution were added respectively into above groups to compare the relaxant effect of these vasodilators on radial artery spasm. Secondly，the other 40 vessel rings were used for spasm prevention experiment with 10 rings in each group. All the 40 vessel rings were dipped in above 4 groups. After 30 minutes，phenylephrine was added to the Organ-Bath to reach final concentration of 10-3 mol/L. Time-dependent constriction of the vessel rings were compared to examine the prevention effect of these vasodilators on radial artery spasm. Results In the spasm relaxation experiment, vessel ring spasm relaxed most quickly in NVC group （P＜ 0.01）. Vessel rings in MIN group relaxed more slowly but steadily （P＜ 0.05）. Vessel rings in PHE group relaxed most slowly （P＜0.01）. And there was no relaxation in the control group. In the spasm prevention experiment，vessel rings in the control group contracted （spasm） 100% immediately after phenylephrine administration. Vessel rings in MIN group contracted immediately after phenylephrine administration too，but slower than the control group（P＜0.01）. Vessel rings in NVC group did not contract right after phenylephrine administration，but the sedentary tension of these vessel rings gradually increased 120 minutes after phenylephrine administration，and vessel ring contraction reached 46.89% 240 minutes after phenylephrine administration. There was no vessel ring contraction in PHE group. Conclusions All the vasodilators in our experiment are effective for the prevention and treatment of radial artery spasm to different degree，but each medication has its own characteristics，vasodilatation result and time-dependent effect. NVC is most effective to dilate radial artery which has been in spasm state, while radial artery pretreated by PHE is least to become spasm after being stimulated.
Abstract： Objective To investigate the cause, treatment， and prevention strategy of early left ventricular rupture after mitral valve replacement （MVR）. Methods We retrospectively analyzed clinical data of 7 patients who had early left ventricular rupture after MVR， among a total of 2 638 MVR patients， between May 1981 and November 2010 in General Hospital of Shenyang Military District. There were 2 male patients and 5 female patients with their age ranging from 28 to 71 years old. One patient was New York Heart Association （NYHA） functional classⅡand 6 patients were NYHA functional classⅢ. Preoperative echocardiography showed that their left ventricular ejection fraction （LVEF） was 49%-60% and their left ventricular end diastolic volume （LVEDV） was 29-42 ml. All the patients underwent prothetic valve replacement under moderate hypothermia， general anesthesia and extracorporeal circulation. Results All the 7patients underwent surgical repair for their early left ventricular rupture. There were 2 patients with TypeⅠ， 4 patients with TypeⅡ， and 1 patient with TypeⅢleft ventricular rupture. Four patients died of hemorrhagic shock or low cardiac output syndrome. Three patients were successfully healed and discharged from hospital 7-15 days after the operation. The 3 surviving patients were followed up for 4.5-18.0 years, and they all had good general condition and satisfactory quality of life. No late pseudo-aneurysm was found during follow-up. Conclusions Early left ventricular rupture is difficult to repair with a high mortality. Effective prevention strategy should be applied to avoid it as much as possible. Once left ventricular rupture occurs during the surgery， extracorporeal circulation should be quickly established， and it’s possible to save patients’ life by reliable intracardiac and epicardial repair according to patients’ individual condition.