Magnetic resonance imaging of spiral vein graft bypass of superior vena cava in fibrosing mediastinitis

Magnetic resonance imaging (MRI) was used for postoperative evaluation of spiral vein grafts in three patients with fibrosing mediastinitis who had undergone bypass of the superior vena cava (SVC) for SVC syndrome. The MRI images, obtained without ECG triggering, were compared retrospectively with postoperative bilateral arm venograms. Patent grafts were identified by MRI in all patients. Significant stenoses at innominate vein-spiral vein graft anastomoses in two patients were better demonstrated by venography than by MRI. MRI shows promise as a non-invasive technique for postoperative evaluation of spiral vein bypass grafts.     

Superior vena cava syndrome: a rare complication of saphenous vein graft stenting: a case report

Rupture of coronary artery bypass graft during percutaneous coronary intervention is a rare but serious complication. These perforations are often associated with myocardial infarction, pericardial tamponade, immediate or delayed, emergency bypass surgery and even death. We report an interesting case where perforation of a saphenous vein graft occurred after direct stenting, resulting in a very rare complication of superior vena cava (SVC) syndrome.     

Comparison of the rheologic parameters in left internal thoracic artery grafts with those in saphenous vein grafts.

BACKGROUND: Left internal thoracic artery (LITA) grafts have superior patency to saphenous vein grafts (SVG). Because shear stress augments the release of nitric oxide throughout the LITA endothelium, shear stress and shear rate in coronary artery bypass grafts (CABG) may play an important role in the higher patency, so the aim of the present study was to evaluate and compare the rheologic parameters in CABG using LITA and SVG. METHODS AND RESULTS: Rheologic examinations were done in 197 patients using a vacuum-suction glass tube viscometer after CABG surgery was completed. Shear stress and shear rate were calculated from the geometry of the graft, blood flow in the graft and blood viscosity. Of 197 patients, 177 underwent LITA grafting to the left anterior descending artery (LAD) and 160 had SVG anastomosis to coronary arteries. Mean wall shear stress in the LITA grafts to the LAD (13.8+/-1.0 dyne/cm2) was nearly 4-6-fold larger than that in the SVG grafts. Mean shear rate (559.1+/-57.0 s(-1)) of LITA-LAD grafts was approximately 2-3-fold higher than that of SVG. CONCLUSION: These results suggest that high wall shear stress and shear rate play an important role in the higher patency rate of LITA grafts.     

Hemodynamics and coronary blood flow during exercise after coronary artery bypass grafting with internal mammary arteries in children with Kawasaki disease

BACKGROUND. Saphenous vein grafts (SVG) and internal mammary artery (IMA) grafts have been used for coronary artery bypass grafting. In adult patients with bypass grafting for atherosclerotic coronary artery disease, IMA grafts have been reported to have long-term patency; however, results are conflicting on whether the graft is sufficient to meet increased myocardial oxygen demand during exercise. There have been no studies on hemodynamics and blood flow during exercise after bypass grafting with IMA in pediatric patients with Kawasaki disease. METHODS AND RESULTS. We studied 17 pediatric patients with Kawasaki disease (average age, 7.5 +/- 3.1 years), who underwent coronary artery bypass grafting with the IMA. The average number of coronary artery bypass grafts was 2.1 +/- 0.7/patient. For all patients, the left IMA was anastomosed to the left anterior descending coronary artery; for eight patients, the right IMA was also anastomosed to the right coronary artery. In addition, 11 SVGs were used. The postoperative patency rates after 1 month were 100% with the IMA graft and 91% with SVG. One year after the operation, the patency rates were 100% with IMA and 50% with SVG. Hemodynamics during exercise were measured with a bicycle ergometer, and coronary sinus blood flow was measured by the continuous thermodilution method in six patients. The relation between delta LVEDP (the difference between left ventricular end-diastolic pressure at rest and during exercise) and delta SVI (the difference between the stroke volume index at rest and during exercise) was analyzed. Four of six patients had reduced cardiac function before operation (delta LVEDP, positive; delta SVI, negative). However, after the operation, all patients demonstrated improvements in cardiac function during exercise (delta LVEDP, positive; delta SVI, positive). Coronary sinus flow per left ventricular mass increased after operation from 70 +/- 46 to 87 +/- 56 ml/min at rest (p less than 0.05) and from 139 +/- 118 to 183 +/- 150 ml/min during exercise (p less than 0.05). CONCLUSIONS. In conclusion, this study reveals improvements in both hemodynamics and coronary blood flow during exercise after coronary artery bypass grafting with IMA grafts in pediatric patients with Kawasaki disease.     

Long-term patency of saphenous vein and left internal mammary artery grafts after coronary artery bypass surgery: results from a Department of Veterans Affairs Cooperative Study

OBJECTIVES: This study defined long-term patency of saphenous vein grafts (SVG) and internal mammary artery (IMA) grafts. BACKGROUND: This VA Cooperative Studies Trial defined 10-year SVG patency in 1,074 patients and left IMA patency in 457 patients undergoing coronary artery bypass grafting (CABG). METHODS: Patients underwent cardiac catheterizations at 1 week and 1, 3, 6, and 10 years after CABG. RESULTS: Patency at 10 years was 61% for SVGs compared with 85% for IMA grafts (p < 0.001). If a SVG or IMA graft was patent at 1 week, that graft had a 68% and 88% chance, respectively, of being patent at 10 years. The SVG patency to the left anterior descending artery (LAD) (69%) was better (p < 0.001) than to the right coronary artery (56%), or circumflex (58%). Recipient vessel size was a significant predictor of graft patency, in vessels >2.0 mm in diameter SVG patency was 88% versus 55% in vessels 2.0 mm in diameter.     

Coronary artery bypass graft pseudoaneurysm communicating with the right atrium: A case report and review

We report a pseudoaneurysm of the right coronary artery bypass graft with fistulous drainage into the right atrium. This patient presented with an acute myocardial infarction in a different vascular territory. Cardiac catheterization led to the diagnosis of the pseudoaneurysm. A review of pseudoaneurysms of aortocoronary bypass grafts is presented. © 1996 Wiley-Liss, Inc.     

Long-term survival in coronary artery bypass grafting surgery depending on the second conduit used

There is still debate whether radial artery (RA) conduits are better grafts then saphenous vein grafts (SVG) as a second conduit in coronary artery bypass grafting (CABG) surgery. Although it has been confirmed that RA grafts have significantly better patency over years, only some observational studies have associated RA use with reduced all-cause mortality. So far, no randomized controlled trial (CRT) has confirmed significantly better survival for RA graft recipients versus SVG recipients. Therefore, we have to wait for the results of the ongoing ROMA (CRT) study, to draw relevant conclusions about the impact of the second graft on long-term survival in patients undergoing CABG surgery.     

Noninvasive assessment of aortocoronary bypass graft patency using pulsed Doppler echocardiography.

To evaluate noninvasively aortocoronary bypass graft patency, pulsed Doppler echocardiography was performed at the time of postoperative coronary angiography in 120 consecutive patients. Ultrasonic examination of 163 vein grafts was possible. One hundred twenty-seven patent and 14 occluded grafts were correctly identified. Eleven patent grafts could not be recorded, and 11 occluded grafts were falsely diagnosed as patent. The method had an overall sensitivity of 92% and a specificity of 56%. This high sensitivity level may be increased to almost 100% by enhanced technical skill and experience. The low specificity level, although the method must be tested in a larger number of bypass grafts, stresses the importance of correctly identifying other sources of diastolic blood flow. Diastolic flows from the superior vena cava, internal mammary veins, tricuspid valve, mitral valve and right ventricle may be eliminated by careful adjustment of the depth, site and size of the pulsed Doppler electronic sampling gate. Standard echocardiographic landmarks for avoiding confusion with the coronary arteries are also described.     

Traumatic giant pseudoaneurysm of innominate artery

A 20-year-old man developed a giant pseudoaneurysm of the innominate artery 5 months after blunt chest trauma, causing severe respiratory distress and superior vena cava compression symptoms. The patient was managed with hypothermia and low flow cardiopulmonary bypass resulting in a successful outcome.     

Superior vena cava syndrome secondary to saphenous venous graft aneurysm with right atrial fistula.

Mega-aneurysms of saphenous vein grafts (SVGs) to coronary arteries are rare complications of bypass surgery. We report the development of superior vena cava syndrome secondary to an SVG mega-aneurysm with concomitant fistulous communication to the right atrium. Successful treatment was achieved by coil embolization and chronic anticoagulation.     

Spontaneous late thrombolysis of an occluded saphenous vein graft subsequent to acute myocardial infarction treated with percutaneous coronary intervention to the native culprit vessel

A 67-year-old male with prior history of myocardial infarction and coronary artery bypass grafting (individual vein grafts to the left anterior descending artery [LAD] and right coronary artery) presented with an acute anterior ST elevation myocardial infarction and cardiogenic shock. The vein graft to the LAD was occluded with heavy thrombus burden and there was severe native CAD. Given the degree of thrombus burden and other anatomic considerations, percutaneous intervention with stenting was performed to the native proximal LAD. Three months later, after complaining of atypical chest pain, repeat angiogram revealed a spontaneous widely patent vein graft to the LAD and occluded proximal LAD.     

Secondary endovascular repair of a reconstructed superior vena cava in a patient with a malignant thymic epithelial neoplasm

Thymic epithelial tumors can cause venous obstruction from compression or direct invasion of the superior vena cava (SVC) or the innominate veins. We report a case of a 40-year-old patient with a Masaoka stage III thymoma that resulted in obstruction of the left innominate vein and extrinsic compression of the SVC. All macroscopic tumors were resected together with ligation of the left innominate vein and reconstruction of the SVC with an ePTFE graft. Early graft thrombosis occurred in the first postoperative month with clinical signs of SVC syndrome. Endovascular repair was performed with the deployment of self-expanding nitinol stents, resulting in immediate relief of symptoms. The stented graft has remained patent for a follow-up period of 7 months.     

Giant aneurysm of a saphenous vein graft with fistulization into the right atrium: differential diagnosis and treatment]

The aneurysm of an aortocoronary saphenous vein graft is a rare but potentially fatal complication of coronary artery bypass grafting. This case came to our observation after a single episode of hypotension, followed by dyspnea in a man previously operated on for coronary artery bypass grafting. A para-hilar mass was found on routine roentgenogram. The spiral computed tomographic scan was suggestive for aortic pseudoaneurysm. The correct diagnosis was obtained by cardiac catheterization showing a giant graft aneurysm determining compression and fistulous communication into the right atrium. The difficult diagnosis and the surgical treatment are discussed.     

Off-pump resection of aorto-saphenous vein graft pseudoaneurysm

Pseudoaneurysms of saphenous vein grafts are rare. We present the case of a 58-year-old man who presented with recurrent angina nine years following quadruple coronary artery bypass graft surgery in 1983. He was found to have an aneurysm arising from the ascending aorta. The patient underwent off-pump aorto-saphenous vein pseudoaneurysm resection and redo coronary artery bypass grafts.     

Intravascular lithotripsy in saphenous vein grafts and graft stent failure: A case series

The long-term patency of saphenous vein grafts (SVGs) is poor compared to arterial bypass grafts. Re-do coronary artery bypass graft surgery (CABG) is high risk, thus graft failure often requires revascularization with percutaneous coronary intervention (PCI). While PCI to the native vessels is preferable, PCI to SVGs is sometimes necessary despite being associated with a high incidence of stent failure. While early SVG degeneration is associated with friable disease, calcification becomes an increasing problem in older grafts. Intravascular Lithotripsy (IVL) has been demonstrated to be safe and effective in the treatment of calcified native coronary artery disease (CAD). We present the first case series of five patients undergoing PCI to de novo SVG disease or SVG stent failure utilizing IVL for calcium modification.     

Five-year follow-up after long plaque-bridging coronary arteriotomy for diffuse coronary artery disease

Long arteriotomy bridging a stenotic plaque or segment may improve runoff in diffuse coronary artery disease. However, patency might be impaired due to vascular wall pathology. OBJECTIVE: To determine the patency rates of plaque-bridging arteriotomy compared to conventional coronary artery bypass grafting. METHODS: Between May 1995 and December 1998, 104 patients with a mean age of 65 +/- 7 years received a long arteriotomy extending over a heavily plaqued area in an effort to treat their diffuse coronary artery disease. The length of the arteriotomy ranged from 14 mm to 40 mm. We retrospectively analyzed the intra-individual bypass graft patency rates by multidetector-computed tomography or coronary angiography. RESULTS: The mean follow-up was 5 years. There were 5 (4.8 %) early and 10 (9.6 %) late deaths, three non-cardiovascular. Graft patency for internal thoracic artery (ITA) to left anterior descending artery (LAD) (plaque-bridging) was 94.8 %, for saphenous vein graft (SVG) to circumflex artery (CX) (plaque-bridging) 67 %, and SVG to right coronary artery (RCA) (plaque-bridging) 79.5 %. Graft patency for ITA to LAD (conventional) was 94.9 %, for SVG to CX (conventional) 72.4 %, and SVG to RCA (conventional) 75 %. Freedom from angina was 82.8 % (n = 58/70), freedom from myocardial infarction was 95.7 % (n = 67/70), freedom from reintervention was 91.4 % (n = 64/70) and freedom from reoperation was 100 % (n = 70/70). CONCLUSION: Diffuse coronary artery disease can be treated by extending the arteriotomy over the plaques, with graft patency rates comparable to bypass grafts onto less diseased segments.     

Ruptured saphenous venous graft pseudoaneurysm presenting as a pulsatile chest mass

A 72‐year‐old man with prior history of coronary artery bypass grafting and sternal wire infection presented with non‐ST‐segment elevation myocardial infarction. His coronary angiogram revealed stenosis of the distal left main coronary artery (LMCA) and a pseudoaneurysm of saphenous venous graft (SVG) to right posterior descending artery. Patient developed ventricular fibrillation during admission, and postcardiopulmonary resuscitation, a pulsatile chest mass was observed which was diagnosed with computed tomography as a chest wall collection resulting from rupture of the pseudo‐aneurysm. He underwent percutaneous coronary intervention of the LMCA with drug‐eluting stents followed by successful coil embolization of the SVG pseudoaneurysm. Patient had an uneventful recovery postprocedure.     

Aneurysm of saphenous vein graft to coronary artery presenting as non-q-wave myocardial infarction secondary to mass effect

Large aneurysms (>4 cm) of saphenous vein grafts (SVG) to coronary arteries are a rare complication of coronary artery bypass graft surgery (CABG). A 64-year-old male, status post-CABG 14 years ago, presented with dyspnea and diaphoresis. Pneumonia and non-Q-wave myocardial infarction (MI) were diagnosed. Cardiac catheterization and chest computed tomography demonstrated a 5 × 7-cm aneurysm of a SVG. At the time of surgery, the left internal mammary artery (grafted to the left anterior descending artery) was found to be stretched tautly over the aneurysm, resulting in impaired flow. The aneurysm was successfully resected. This is the first published case implicating a SVG aneurysm as the direct cause of a MI by mass effect.     

The acute and chronic effects of G-lasing on femoral vein grafts in dogs

Each year, 5% of all coronary artery bypass operations are repeat procedures, and 15%-30% of coronary artery vein grafts occlude within the first eighteen months postoperatively. To evaluate the macroscopic and histologic effects of G-lasing on vein grafts and their patency, femoral veins were used to bypass bilaterally induced stenoses of femoral arteries in 10 dogs. The left vein grafts were G-lased with a 1.5 mm, hot-tipped argon laser at 5 watts for ninety seconds, while the right grafts were used as the controls. Acutely, each vein graft demonstrated no evidence of charring or perforation. The percentage of endothelium present in the G-lased vein grafts was consistently less than 5%, whereas the control vein grafts had an average of 70%. After ten weeks, the animals were sacrificed, and the vein grafts were evaluated for histologic changes and patency. There were no significant microscopic differences between the G-lased and control vein grafts. A statistically significant difference in graft patency was not achieved between G-Lased and control vein grafts at 10 weeks, but only a small number of grafts were studied. Further studies will be needed to evaluate the effects of G-lasing on the long-term patency of vein grafts.     

微创经左胸小切口非体外循环单支、多支冠状动脉旁路移植术33例

目的 探讨左侧肋间小切口非体外循环单支、多支冠状动脉旁路移植术的安全性和可行性。方法 回顾性分析2014年5月~2019年10月左胸前外侧小切口非体外循环下冠状动脉旁路移植术33例资料。单支病变17例,多支病变16例。左胸前外侧小切口6cm-10cm,直视下获取左乳内动脉(LIMA),完成LIMA-左前降支(LAD)吻合,升主动脉（Ao）-大隐静脉(SVG)序贯-对角支(D)或中间支（ICA）-钝缘支(OM)-后降支(PDA)或左室后支(PLV)共2~4支旁路移植血管吻合。结果 全组LIMA-LAD桥32例,Ao-SVG-LAD 1例。Ao-SVG-D 2例,Ao-SVG-OM 2例、Ao-SVG-OM-PDA 2例,Ao-SVG-ICA-PDA 3例,Ao-SVG-D-OM-PDA 4例,Ao-SVG-D-OM-PLV 3例。33例手术均顺利完成,围术期无死亡、心肌梗死、脑卒中、呼吸衰竭、肾功能衰竭、切口感染等并发症。术后呼吸机时间7h~18 h(9.14±3.82)h;ICU时间6h~20 h（12±8）h。术后住院5d~11d(8±3)d。出院时复查冠状动脉CT,33例均提示左乳内动脉桥、大隐静脉序贯桥通畅性良好。随访3个月~3年,平均8个月,无死亡、心绞痛和心肌梗死。30例复查冠状动脉, LIMA桥、SVG序贯桥通畅性良好。结论 左侧肋间小切口非体外循环下多支冠状动脉旁路移植术安全可行。