Hidenori Sako

Acute myocardial infarction due to left main coronary artery occlusion. Therapeutic strategy.

OBJECTIVE Acute myocardial infarction due to left main coronary artery occlusion remains catastrophic and mostly fatal due to severe cardiogenic shock and arrhythmia. METHODS We studied 13 patients undergoing coronary artery bypass grafting for acute myocardial infarction due to left main coronary artery occlusion to clarify the optimal management of these difficult patients. RESULTS In-hospital mortality was 46.2% (6/13). Revascularization was achieved by catheter intervention followed by bypass surgery in 7, and bypass surgery alone in 6. Two bypass surgery patients without catheter intervention had collateral flow to the left coronary artery, with the right coronary artery dominant. The time from onset to recanalization in the survival group was significantly shorter than in the early death group. CONCLUSIONS Emergency intervention to preserve left ventricular function or right coronary artery dominant and collateral blood flow to left coronary arteries is important for improving the prognosis of patients with acute myocardial infarction due to left main coronary artery occlusion. If residual left main coronary artery stenosis is significant or other proximal coronary stenosis exists after catheter intervention, early coronary bypass surgery may improve long-term survival.

Limb ischemia and reperfusion during abdominal aortic aneurysm surgery

PurposeAbdominal aortic aneurysm (AAA) surgery involves ischemia and reperfusion of the lower extremities, but assessing the pathophysiological changes is difficult. We evaluated the extent and time course of ischemia–reperfusion injury of the lower extremities during AAA surgery.MethodsTo monitor oxygen metabolism, two near-infrared spectroscopy (NIRS) probes were positioned on each calf muscle of nine patients undergoing AAA surgery. Lactate and pH were also measured in both iliac veins.ResultsNear-infrared spectroscopy signals responded sensitively to aortic cross-clamping and declamping. Lactate increased gradually and exponentially during aortic cross-clamping, and reconstruction of the first iliac artery resulted in a further but transient increase in ipsilateral venous lactate. The time course of the pH level after declamping was almost a mirror image of that of lactate. Reconstruction of the first iliac artery did not affect the contralateral NIRS signals, lactate, or pH.ConclusionsNear-infrared spectroscopy may be useful for monitoring limb ischemia during AAA surgery. The transient increase in lactate and the transient decrease in pH after first declamping may contribute to the mechanism of declamping shock. The fact that first declamping did not affect measurements on the other side shows that contralateral ischemia progresses steadily after reconstruction of the first iliac artery. Therefore, reconstruction of the second iliac artery should be done as soon as possible.

Stented elephant trunk method for multiple thoracic aneurysms

Stent-grafting and open graft replacement was introduced to reduce the complications of suture anastomosis in the descending aorta. We applied this technique in the treatment of a patient with multiple thoracic aneurysms. The elephant trunk procedure was used for thromboexclusion. A single branched graft was placed easily without twisting. In patients with aneurysms at both the proximal and distal thoracic aorta, combined stent-grafting and open graft replacement is an excellent approach.

Effect of Prostaglandin E1 on Ischemia–Reperfusion Injury During Abdominal Aortic Aneurysm Surgery

ObjectiveAbdominal aortic aneurysm (AAA) surgery subjects the lower extremities to ischemia and reperfusion. Although it is not extensive or prolonged, ischemia of the lower extremities during aortic cross-clamping is gradually and steadily induced. We studied the effects of prostaglandin E1 (PGE1) on ischemia–reperfusion injury of the lower extremities during AAA repair.MethodsDuring AAA surgery, two near-infrared spectroscopy probes were positioned on each calf muscle to monitor oxygen metabolism in the lower extremities. We also measured lactate concentration in both iliac veins.ResultsNear-infrared spectroscopy signals responded sensitively to aortic cross-clamping and declamping. Lactate increased time-dependently during aortic cross-clamping. The continuous venous administration of PGE1 (20 ng/kg per minute) inhibited the accumulation of lactate during aortic cross-clamping. Declamping of the first iliac artery resulted in a further but transient increase in ipsilateral venous lactate, which may be one component in the mechanism of declamping shock. Prostaglandin E1 eliminated the transient increase in ipsilateral lactate. The administration of PGE1 inhibited the contralateral accumulation of lactate after first declamping, and the lactate level decreased gradually before the second declamping.ConclusionsProstaglandin E1 seems to have a protective effect against ischemia–reperfusion injury of the lower extremities during AAA surgery.

An easy, safe, and sure way of open stent grafting: chain-stitch bonding with a balloon catheter.

A modified transaortic graft insertion technique with a nephrostomy balloon catheter is presented herein. The graft, which has a Z stent at its end, is bound to the catheter with a chain stitch and then is inserted into the descending aorta under transesophageal echographic observation. Unlacing the chain stitch easily deploys the stented graft. This technique is safer and more reliable than other current methods.

Successful open stent grafting of a right aortic arch and a descending aortic aneurysm originating from a Kommerell's diverticulum: Report of a case

Abstract The case of a 43-year-old man found to have an aneurysm developing from a Kommerells diverticulum at the origin of an aberrant retroesophageal left subclavian artery is reported herein. The aneurysm was treated by the open stent grafting technique and complete revascularization was achieved.

An implantation of DDD epicardial pacemaker through ministernotomy in a patient with a superior vena cava occlusion.

SAKO, H., et al.: An Implantation of DDD Epicardial Pacemaker Through Ministernotomy in a Patient with a Superior Vena Cava Occlusion. We successfully implanted a DDD epicardial pacemaker through a limited lower sternotomy in a patient whose superior vena cava had been occluded. Both epicardial leads were connected to the generator placed in the existing subcutaneous pocket on the left pectoral region through the second intercostal space. This approach provided excellent exposure and easy access to both the right appendage and the right ventricle. The combined procedure of epicardial DDD pacemaker implantation through a limited lower sternotomy with placement of the generator in the pectoral subcutaneous pocket is one of the better methods when intravenous lead implantation is difficult. (PACE 2003; 26:778–780)

Pinhole rupture of aortic root aneurysm with severe atherosclerotic change

We report two cases of the rupture of calcified aortic root aneurysms that were successfully treated by emergency operations. One patient underwent Bentalls operation, and for the other, we performed a valve-sparing operation. Because their aneurysms revealed pear-like configurations with aortic regurgitation, the findings were consistent with annuloaortic ectasia (AAE). However, both cases were unlike typical AAE in that the aortic walls showed severe atherosclerotic change, with little sign of cystic medial necrosis. It was very interesting that each rupture point was a very small pinhole originating from one of the atherosclerotic ulcers.

Denervation and reinnervation of the heart after aortic surgery, estimated by 123I-metaiodobenzylguanidine scintigraphy.

PurposeTo investigate whether sympathetic nerve injury occurs during aortic surgery and how reinnervation takes place afterward.MethodsImaging with 123I-metaiodobenzylguanidine (MIBG) was performed in 12 patients (aortic group) who underwent aortic surgery (ascending replacement 3, ascending-arch replacement 9) before and 3 weeks after surgery. In 8 of 12 patients, MIBG scintigraphy was performed 1 and 2 years after surgery. Twelve patients (control group) who underwent open-heart surgery (mitral valve repair: 11; tricuspid valve replacement: 1) were studied using MIBG scintigraphy. The heart-to-mediastinum (H/M) activity ratio was obtained from planar images. The myocardial single-photon-emission computed tomography image was divided into five segments and the regional tracer uptake was scored from 0 = absent to 3 = normal uptake.ResultsNo significant difference in the H/M ratio in either early and delayed planar scans was observed between both groups before surgery. The H/M ratios significantly decreased 3 weeks after surgery in the aortic group, whereas there was no significant change in the control group. The H/M ratio did not recover to the preoperative level within 2 years. In these 8 patients, the regional uptake of MIBG improved in the anterior and septal regions 1 year after surgery.ConclusionDuring ascending or ascending-arch replacement, the sympathetic nerve was globally denervated and slight reinnervation was observed within 2 years. The anterior and septal regions showed a rapid reinnervation, whereas other regions did not.

Reversal of Delayed-onset Paraplegia with Thrombectomy of an Interposed Graft for the Intercostal Artery after Thoracic Descending Aortic Aneurysm Repair

A 78-year-old woman who had previously undergone prosthetic graft replacement of the total aortic arch was admitted to repair a chronic expanding type IIIb dissecting aneurysm. Firstly the patients abdominal aorta was replaced with a prosthetic graft without any complications, then the thoracicdescending aorta was repaired five months later. Surgery for the thoracic descending aorta was performed with distal perfusion, cerebrospinal fluid drainage, somatosensory evoked potential (SEP) monitoring and reimplantation of three pairs of intercostal arteries. During surgery, SEP showed no significant changes, and the patient awoke without paraplegia three hours after the surgery. However, she developed bilateral complete paraplegia eight hours after the surgery. Reexploration demonstrated thrombo-occlusion of the sidearm graft for reimplantation of the Th10 intercostal artery. After thrombectomy of the sidearm graft, there was gradual neurological recovery and the patient was ambulatory when discharged. Quick treatment to restore the spinal cord blood supply promoted recovery from paraplegia.