ABSTRACT
Neointimal hyperplasia is the principal mechanism of graft failure in coronary artery bypass surgery. Systemic administration of cilostazol has been reported to suppress neointimal hyperplasia in some vascular injury models. We sought to deliver cilostazol locally in an attempt to augment its beneficial effect to inhibit neointimal hyperplasia at an anastomotic site. We examined whether the external application of a novel cilostazol-eluting film can inhibit neointimal hyperplasia in a vascular anastomosis model. Canine femoral artery graft interposition was performed in 20 beagle dogs, assigned to 4 groups of 5 dogs each : a graft interposition without copolymer of L-lactide and ε-caprolactone (P (LA/CL) ) film (control group) and groups with P (LA/CL) film containing cilostazol of either 10 mg, 40 mg, or 80 mg doses. All the cilostazol-eluting film with 10 mg, 40 mg, and 80 mg dose groups had a reduced intima/media ratio compared to the control group (0.15±0.03, 0.11±0.03, and 0.12±0.03, vs. 0.31±0.03, <i>p</i><0.05). Immunohistochemical analyses for proliferating cell nuclear antigens revealed reduced cellular proliferating activity associated with decreased α-actin positive cells in the cilostazol-eluting film groups compared to the control group. External application of cilostazol-eluting film can inhibit neointimal hyperplasia, at least in part, by inhibiting smooth muscle cell proliferation in the intima.
ABSTRACT
We conducted a clinical study on a newly developed large diameter vascular graft (Triplex<sup>®</sup>, Terumo Corporation, Tokyo, Japan) with a non-biodegradable material used as sealing material, to evaluate its effectiveness and safety. Triplex<sup>®</sup> grafts were implanted in 170 patients with either aneurysmal or occlusive arterial disease in either the thoracic artery, abdominal artery or iliac arteries, between October 2001 and March 2003. The patients consisted of 141 men and 29 women with an average age of 69.0±10.0 years old (mean±SD). In 82 patients, Triplex<sup>®</sup> was implanted for the thoracic artery area, in 88, for the abdominal artery area. The cumulative graft patency rate 12 months after implantation was 100.0% in each area, there was no any abnormality such as occlusion or rupture from the trunk of Triplex<sup>®</sup>. The distension ratio, which is the index of the dilatation resistance, was 1.03±0.06 as a whole (<i>n</i>=139), 1.03±0.06 in the thoracic artery area (<i>n</i>=73), 1.03±0.06 in the abdominal artery area (<i>n</i>=66). In other words the dilatation of Triplex<sup>®</sup> was hardly observed. As manipulability during the operation, the following characteristics were evaluated; anastomosis, resistance to fraying, hemorrhage, conformability with the host vessel. Triplex<sup>®</sup> was evaluated as “good” in 75% of all items accounted for 75% or more. A transitory rise thought to be due to the surgical stress immediately after the operation because of the change of temperature and laboratory findings (CRP, WBC) between implantation and discharge was observed, but then recovered to the normal levels of each patients at discharge and the re-elevation was not recognized. In 90 patients, 277 adverse events occurred. Although in 33 adverse events in 21 patients a causal relation with Triplex<sup>®</sup> could not be excluded, most of them were already known events as complications which could occur after operation on the aorta. Therefore, it was confirmed that Triplex<sup>®</sup> has certain advantages: 1) good manipulability, 2) good patency and dilatation resistance, 3) no inflammatory reaction related to Triplex<sup>®</sup>, as a graft for the aorta.
ABSTRACT
Although several methods of stent grafting for patients with distal aortic arch aneurysm have been reported, these methods had several complications such as endoleak, migration, or cerebrovascular accident. We developed a new stent grafting method using the MK stent-graft (Matsui-Kitamura stent-graft, Kitamura Inc., Kanazawa, Japan) following bypass grafting of arch vessels under left heart bypass. We performed this method for 3 patients associated with severe pulmonary dysfunction or renal dysfunction. There were no postoperative complications, endoleak or migration. All 3 patients were discharged in good condition. It is concluded that this method might be useful method for patients with distal aortic arch aneurysm complicated by severe organ dysfunction, or in elderly patients.
ABSTRACT
A 74-year-old woman underwent ascending aortic replacement due to acute type A dissection 2 years previously. She received total aortic arch replacement with open stent grafting of the descending thoracic aorta for enlargement of the residual aortic dissection in the aortic arch and descending thoracic aorta. Operative method and, intra- and post-operative protective method of spinal cord are reported and discussed.
ABSTRACT
A 70-year-old man had undergone prosthetic graft replacement for aneurysm of the descending aorta. Postoperatively he suffered methicillin-resistant <i>Staphylococcus aureus</i> infection. Infection was controlled by antibiotics, and he was followed up in the outpatient clinic. However, he was readmitted due to high fever on the 192nd postoperative day. CT scan revealed abscess formation around the prosthetic graft. The wound was re-explored, and drainage, irrigation and packing with sponges soaked with povidoneiodine solution was performed for 3 days. After that, the prosthetic graft was replaced with a cryopreserved aortic homograft. The postoperative course was uneventful, and he showed no signs of recurrent infection for over 14 months.
ABSTRACT
Lecithinized superoxide dismutase (L-SOD) has a higher affinity for cell membranes than recombinant human superoxide dismutase has. The purpose of this study, is to evaluate the protective effects of L-SOD against ischemia/reperfusion injury in blood-perfused isolated rat heart subjected to 30-min global normothermic ischemia. Fifteen isolated hearts were divided into three groups: group I (<i>n</i>=5), the untreated control group, group II (<i>n</i>=5) received 3, 000 units of L-SOD administered into the perfusion circuit at the beginning of reperfusion, and group III (<i>n</i>=5) received 3, 000 units of L-SOD administered into the perfusion circuit 10min after reperfusion. Left ventricular developed pressure, maximum positive and negative d<i>p</i>/d<i>t</i>, coronary vascular resistance and myocardial water content were assessed in each group. The percent recovery of left ventricular developed pressure in group II was significantly higher than that in group I and group III (77.4±11.1% in group II, 38.2±4.4% in group I, 40.2±4.1% in group III, <i>p</i><0.01). The percent recovery of maximum positive dp/dt in group II was significantly higher than that in group I and group III (70.0±11.2% in group II, 41.8±7.8% in group I, 38.0±5.7% in group III, <i>p</i><0.01). The percent recovery of maximum negative d<i>p</i>/d<i>t</i> in group II was also significantly higher than that in group I and group III (74.9±11.0% in group II, 41.3±8.0% in group I, 46.3±5.9% in group III, <i>p</i><0.01).There was no significant difference of coronary vascular resistance or myocardial water content among the three groups. These results suggest that L-SOD administered at the time of reperfusion has protective effects against ischemia/reperfusion injury in the isolated rat heart.
ABSTRACT
We evaluated the efficacy of combined antegrade and retrograde intermittent cold cardioplegia for patients with prolonged aortic cross-clamping. Thirty patients with cross-clamping time of more than 4h were divided into three groups according to the method of cardioplegia. Antegrade crystalloid cardioplegia was performed in 9 cases, combined antegrade and retrograde crystalloid cardioplegia was performed in 5 cases, and combined antegrade and retrograde cold blood cardioplegia was performed in 16 cases. There was no statistical difference in mean aortic cross-clamping time among the three groups. The hospital mortality was 33% in the antegrade crystalloid group, 20% in the combined crystalloid group, and 0% in the combined blood group. There was a significant statistical difference in the hospital mortality between the antegrade crystalloid and combined blood group. The incidence of low cardiac output syndrome (LOS) was 67% in the antegrade crystalloid group, 20% in the combined crystalloid group, and 6% in the combined blood group. There was a significant difference in the incidence of LOS between antegrade crystalloid and combined blood groups. The recovery rate of spontaneous rhythm after the release of the cross-clamp was also significantly greater in the combined blood group than in the antegrade crystalloid group. In conclusion, combined antegrade and retrograde intermittent cold cardioplegia provides excellent myocardial protection for patients with prolonged aortic cross-clamping.
ABSTRACT
Primary end-to-side anastomoses between the left upper pulmonary vein and left atrium performed in 21 puppies with continuous 5-0 polydioxanone (PDS) or polypropylene (PRO). Animals were sacrificed at 1, 7 and 28 days after operation. Stenosis occurred in one of 5 animals of the PDS group at 7 days and 28 days respectively, and one of 5 animals of the PRO group at 28 days. There was no significant difference between the two groups in terms of anastomosis patency. Histological examination showed slight tissue reaction and fibrosis surrounding the sutures in both groups. This study suggests that the absorbable monofilament suture material, in particular PDS, is useful for the repair of low pressure circulatory system and will not cause the stenosis of the anastomotic site.
ABSTRACT
In the past 13 years, 17 patients underwent reoperation after intracardiac repair, including reconstruction of the right ventricular outflow tract. Primary diagnoses of the cardic anomalies were tetralogy of Fallot (TOF) (8 patients), extreme type (TOF) (4 patients), TOF with absent pulmonary valve (1 patient), double outlet right ventricle (DORV) (2 patients), truncus arteriosus (1 patient) and transposition of the great arteries (TGA) (1 patient). Patients were divided into 4 groups based on the surgical procedures for reconstruction of the right ventricular outflow tract as follows: Group A, porcine valved conduit; Group B, autologous pericardial valve bearing tube graft; Group C, transannular patch; Group D, outflow patch with pulmomary valvotomy. The main reason for reoperation in groups A and B was pulmonary stenosis due to calcification of the porcine valve or shrinkage of the pericardial tube graft. Average periods between corrective surgery and reoperation were 7 and 13 years in groups A and B, respectively. Reoperation was performed for massive tricuspid regurgitation and residual shunt, 15 and 24 years after previous operations in groups C and D, respectively. Low cardiac output syndrome, proconged right heart and respiratory failure were major postoperative complications in groups A, B and C. Furthermore, one patient in group A and one other in group C died in the long-term period after reoperation. Both patients had had markedly dilated hearts associated with frequent PVCs. In conclusion, earlier reoperation for progressive and/or residual lesions should be performed to obtain better surgical outcome and quality of life of the patients.