Keiichi Akaiwa

Strategy for Isolated Iliac Artery Aneurysms

We retrospectively reviewed 41 patients with isolated iliac artery aneurysms presenting over a 21-year period. The mean age was 72 years. Mean aneurysmal diameter was 6.0 cm (range, 3.2–13 cm). The aneurysms were located in the common iliac artery in 31 patients, internal iliac artery in 7, and both arteries in 3. Rupture occurred in 20 patients (49%). The frequency of rupture of isolated iliac artery aneurysms was significantly higher than that of abdominal aortic aneurysms (8%) during the same period. The 30-day mortality was 9.8%; death in all 4 patients was due to rupture of the aneurysm. The surgical procedure was aneurysmectomy and replacement with a bifurcated prosthetic graft in 24 patients (59%), closure of the common iliac artery with a femorofemoral crossover in 7, minilaparotomy in 3, thromboexclusion in 6, and endoluminal stent-graft repair in one. In contrast to abdominal aortic aneurysms, isolated iliac artery aneurysms can be treated by various methods other than replacement with a bifurcated prosthetic graft. When selecting a strategy for such aneurysms, it is important to choose an approach appropriate to the location and risk, because of the frequency of rupture.

Moderate cerebral venous congestion induces rapid cerebral protection via adenosine A1 receptor activation.

Stroke is a devastating complication in cardiovascular surgery, and neuronal damage is worsened by intracranial pressure elevation caused by cerebral venous circulatory disturbances (CVCD). However, we have previously reported that CVCD before cerebral ischemia decreases the infarct area. In the present study, focal cerebral ischemia was induced in spontaneously hypertensive rats by filament insertion through the carotid artery. Rats were divided into the following four groups: sham-operated, mild or severe venous congestion (VC), and DPCPX. The DPCPX group received the adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) prior to mild VC. Behavior, infarct volume, edema and S-100 protein were evaluated among the four groups. The infarct volume rates in mild VC and severe VC groups were significantly less than that in sham-operated and DPCPX groups. However, the mortality of the severe VC group worsened in a time-dependent manner. We observed a significant decrease in edema in the mild VC group compared to the DPCPX group. Behavioral scores also indicated that the mild VC group had fewer neurological deficits than the other three groups, including the DPCPX group. We were able to induce rapid cerebral protection via adenosine A1 receptor activation by administering an appropriate degree of VC prior to cerebral ischemia produced by middle cerebral artery occlusion. Our work suggests possible mechanisms by which such effective VC may lead to cerebral protection and adenosine A1 receptor activation.

Thoracic Endovascular Aortic Repair with Homemade Stent Grafts : Early and Mid-Term Outcomes

PurposeWe reviewed our experience with homemade stent grafts in the repair of a variety of thoracic aortic lesions. The objective of this study was to assess the early and mid-term outcomes of this therapy.MethodsFrom 1999 to 2007, homemade stent grafts were inserted in 88 patients with an atherosclerotic aneurysm, dissection, pseudoaneurysm, trauma, or rupture in the thoracic aorta. The endoprostheses were stainless steel Z-stents covered by a polyester graft, and were custom-designed for each patient.ResultsPlacement of stent grafts was technically successful in 81 of the 88 patients (92%). Within 30 days after treatment, 3 patients died, 3 had a cerebral infarction, and 3 had onset of paraplegia or paraparesis. Primary endoleaks were observed in 8 patients (9%). During the mean follow-up period of 32 ± 26 months, 7 patients had persistent endoleaks and 7 had stent-graft migration. The aneurysm-related mortality rate was 7%. The rate of freedom from open-surgery conversion at 32 months was 89.0%.ConclusionsOur early experience with elective and emergency thoracic endovascular aortic repair using homemade stent grafts provided therapeutic benefits to high-risk patients. Endoleaks and stent-graft migrations were the factors most commonly responsible for secondary intervention in the mid-term period. Careful follow-up of patients treated with this approach is needed to avoid major complications in the long term.

Surgical Repair of Subacute Right Ventricular Perforation after Pacemaker Implantation

We report an 84-year-old woman who presented with right ventricular perforation 4 days after pacemaker implantation for syncope due to sick sinus syndrome. Median sternotomy revealed no pericardial effusion, but the pacing lead had penetrated the right ventricle and pericardium. When the pleura was opened, the tip of the lead was seen in the visceral pleura. The lead was cut in the pericardial cavity and extracted from the left subclavian wound together with the generator. The right ventricular perforation was sutured and a temporary pacing lead was placed on the right ventricular wall intraoperatively. Ten days after the surgery, a new pacemaker lead was placed in the ventricular septum via the right axillary vein. Right ventricular perforation is a rare complication after pacemaker implantation. Typically, it occurs at the time of implantation or within 24 hours after implantation. In the present case, the perforation of the right ventricle which needed urgent surgery occurred 4 days after implanting the pacing lead at the right ventricular apex. Great care should have been taken not to overlook this life-threatening complication even more than 24 hours after pacemaker implantation.

Edge-to-edge repair for mitral regurgitation associated with isolated double-orifice mitral valve

We report the case of a patient with severe mitral regurgitation who was diagnosed with double-orifice mitral valve by preoperative transthoracic and transoesophageal echocardiography. During surgery, it was revealed that the mitral valve was divided into 2 orifices, anterolateral and posteromedial, by a fibrous bridging tissue that was supported by the chordae tendineae originating from an accessory middle papillary muscle. The posterior scallop of the anterolateral orifice was prolapsed due to chordal elongation. Six interrupted sutures were made between the anterior leaflet and the posterior leaflet at the prolapsed site. Additional interrupted sutures were made at the sites of 2 clefts, and a ring annuloplasty was added. Residual mitral regurgitation was trivial, and the mean postoperative pressure gradient through each orifice was approximately 6 mmHg. To the best of our knowledge, this is the first case report of an edge-to-edge mitral repair for mitral regurgitation associated with a double-orifice mitral valve.

Remission of Palmoplantar Pustulosis after On-Pump Coronary Artery Bypass Grafting in a Patient with Titanium Allergy

Metal allergy is an uncommon problem during surgery. Among them, titanium allergy is said to be rare, but can lead to serious complications, such as palmoplantar pustulosis (PPP). A 69-year-old woman was admitted to our hospital with a chief complaint of chest pain. Coronary angiography showed severe coronary artery disease that required coronary artery bypass grafting (CABG). The patient had a history of orthopedic surgery for left distal radius fracture 2 years previously, which resulted in inflammation on the left arm and PPP. We suspected titanium allergy based on results of skin patch tests and use of titanium alloy in the previous orthopedic operation. The patient underwent CABG without use of permanent metallic material. As a result, her PPP disappeared. In this rare case, it is difficult to identify the exact cause of the improvement in PPP; thus, further studies are required to clarify the mechanism of remission.

A case of a quadricuspid aortic valve identified preoperatively using transthoracic echocardiography

Quadricuspid aortic valve is an extremely rare congenital heart anomaly that often causes valve incompetence, requiring surgical intervention. Care must be taken to avoid surgical complications in patients with quadricuspid aortic valve; thus, preoperative diagnosis is important. A 76-year-old man presented with exertional dyspnea due to aortic regurgitation. Transthoracic and transesophageal echocardiography revealed severe aortic regurgitation caused by quadricuspid aortic valve. To avoid interference with the cardiac conduction system, we performed aortic valve replacement using an ingenious technique, in which pledgeted sutures on the accessory leaflet were placed from outside the sinus of Valsalva to above the aortic annulus. The patient recovered uneventfully and was discharged from the hospital without any complications. While preoperative diagnosis of quadricuspid aortic valve is considered difficult, we identified it preoperatively using transthoracic echocardiography; we were, thus, able to properly prepare for complete atrioventricular block.

Simultaneous aortic valve replacement and pectus excavatum correction in a 76-year-old man.

A 76-year-old man was admitted to our department to undergo surgical treatment for aortic valve regurgitation. On physical examination, a bowl-shaped concavity was noted. Chest computed tomography revealed left-sided heart displacement by severe pectus excavatum with a Haller index of 6.40. Considering the postoperative cardiopulmonary complications that may result from mechanical compression due to uncorrected sternal deformities, we decided to perform a simultaneous aortic valve replacement and pectus excavatum correction. The operation time was long (570 min) and involved a high-volume transfusion due to excessive bleeding caused by resection of the deformed costal cartilages and sternal osteotomy under the use of heparin. The endotracheal tube was removed on the fifth postoperative day, but reintubation was required because of hypercapnea and difficulty in sputum discharge. With the aid of tube feeding for nutritional management, his cardiopulmonary function gradually ameliorated and his general condition improved. Consequently, he was weaned from mechanical ventilation on the 14th postoperative day. The patient is doing well 1 year after surgery. We report on the surgical management for pectus excavatum in adult patients.