Yusuke Tsuru

Endovascular flexible stent grafting with arch vessel bypass for a case of aortic arch aneurysm

The Matsui-Kitamura (MK) stent graft (Kitagawa, Kanazawa, Japan) is designed to fit the curvy portions of the aorta because first-generation rigid skeleton–type stent grafts potentially cause kinking and endoleak as a result of limited flexibility. The MK stent graft consists of a custom-made, self-expandable spiral mesh of a single nitinol wire and thin-walled polyester fabric. We report the first surgical case of aortic arch aneurysm treated with this flexible and curved stent graft after extra-anatomic bypass of the arch vessels to prepare a landing zone for the stent graft.

Epidural cooling for regional spinal cord hypothermia during most or all of descending thoracic or thoracoabdominal aneurysm repair

Abstract Purpose: Hypothermia has some protective effect against ischemia of the spinal cord in thoracoabdominal aneurysm repair. Its method is divided into systemic or regional cooling. Several experimental studies of the regional cooling of the spinal cord have been performed, however, clinical reports are few. The purpose of this study is to evaluate the effect and safety of perfusion cooling of the epidural space during thoracic or thoracoabdominal aortic replacement. Methods: Between January 1998 to June 2001 37 patients (True aneurysm: 18 patients, type B aortic dissection: 19 patients) underwent thoracic or thoracoabdominal aortic replacement with an aid of epidural perfusion cooling. The age ranged from 23 to 78 years old with a mean age of 61 years old. Separate perfusion of upper and lower body was used in all cases. Temperature was lowered to around a 31°C or 32°C. In cases where proximal cross-clamping was danger, deep hypothermic circulatory arrest was used. Results: Ten patients underwent most or all of descending thoracic aneurysm repair with no spinal cord injury and hospital death. Number of patients of the Crawford type I, type II, and type III were 14, 8 and 5 patients, respectively. One Crawford type II patient was complicated with postoperative spinal cord injury (2.7%). There was one hospital death (2.7%) in Crawford type III. The mean epidural cooling time was 150 minutes, and mean infusion volume of cold saline was 981 cc. The mean lowest cerebrospinal fluid (CSF) temperature was 24.3°C, and mean temperature differences between nasopharynx and CSF was 6.3°C. Conclusion: Perfusion cooling of the epidural space during most or all of the descending thoracic or thoracoabdominal aneurysm repair was effective in reducing postoperative spinal cord injury and a safe method in clinical situations.

Nicorandil pretreatment and improved myocardial protection during cold blood cardioplegia

OBJECTIVE The present study was designed to assess whether pretreatment with nicorandil enhanced myocardial protection provided by cold (15 degrees C) high-potassium (25 mmol/l) blood cardioplegia during open heart surgery. METHODS Subjects were 40 patients with a variety of acquired heart diseases undergoing cardiac surgery involved cardiopulmonary bypass. They were randomly divided into two groups, 25 pretreated nicorandil (0.3 mg/kg) 30 minutes before aortic cross clamping, 15 not pretreated. After aortic cross clamping, the initial dose of cardioplegic solution (10 ml/kg) was administered through the ascending aorta and supplemental doses of cardioplegia (5 ml/kg) given each 30 minutes thereafter. Preoperative and postoperative cardiac troponin-T, myosin light chain 1 and cardiac enzymes were measured and hemodynamic data recorded. RESULTS Postoperative serum creatine kinase and myosin light chain 1 were significantly lower in the nicorandil pretreatment group than in controls. Serum glutamic oxalacetic transaminase and troponin-T were lower and cardiac output was higher after surgery in the nicorandil group, although not statistically significant. CONCLUSION This data suggests that pretreatment with nicorandil enhances the myocardial protection achieved by cold blood cardioplegia.

Successful weaning from inhaled nitric oxide using dipyridamole.

A 33-year-old woman with an atrial septal defect associated with severe pulmonary hypertension underwent suture closure of the defect after assessment of operability by lung biopsy. Postoperative course was complicated by suprasystemic refractory pulmonary hypertension, and she became dependent upon treatment with inhaled nitric oxide. After multiple attempts to withdraw nitric oxide, dipyridamole was administered and blunted the rebound pulmonary hypertension after subsequent nitric oxide withdrawal.

Ascending aortic replacement through right thoracotomy.

A 62-year-old woman with a history of esophageal resection and colon interposition with anterosternal subcutaneous tunnel required replacement of the ascending aorta due to dissecting aortic aneurysm. Preoperative three-dimensional computed tomography enabled us to reveal that right thoracotomy could offer an ascending aortic operation. The patient underwent successful operation under hypothermic circulatory arrest and the right anterolateral thoracotomy provided safe exposure of the diseased ascending aorta even when the suprasternal tunnel precluded conventional median sternotomy.

Concomitant Replacement of the Aortic Root And Aortic Arch With or without Secondary Thoracoabdominal Aorta Replacement

OBJECTIVES Extensive aortic replacement, such as concomitant aortic root and arch replacement, thoracoabdominal aortic repair, and complete thoracic aorta replacement, remains controversial. We studied surgical morbidity and mortality in patients undergoing concomitant aortic root and arch replacement, and those undergoing secondary replacement of the thoracoabdominal aorta after this preceding procedure. SUBJECTS AND METHODS Between January, 1987 and March 1999, 21 patients (mean age: 52 years) underwent concomitant aortic root and arch replacement involving 3 surgical procedures--aortic root replacement with composite graft and arch (n = 12), aortic root replacement with valve sparing and arch (n = 4), or aortic root replacement with composite graft and arch and elephant trunk (n = 5). RESULTS Overall hospital mortality was 4.8%. Six patients (mean age: 42 years) underwent secondary thoracoabdominal aorta replacement after the concomitant root and arch procedure. The mean time until secondary surgery was 9.5 months. There was 1 hospital death. CONCLUSION Concomitant replacement of the aortic root and arch, or secondary replacement of the thoracoabdominal aorta after concomitant root and arch replacement can be conducted with low surgical morbidity and mortality.

Commissure holder: an innovative device for aortic valve-sparing technique

The key to obtaining maximal valve coaptation from the aortic valve-sparing procedure is in appreciating the optimal geometry of each component of the aortic root. We describe a new device called the Commissure Holder (patent pending) that aids in the selection of an appropriate graft size and in the determination of the optimal position at which each commissure should be sutured to the graft.

An experimental study on the occurrence of brain edema after retrograde cerebral perfusion

To assess the safety of retrograde cerebral perfusion, the occurrence of brain edema after this procedure was investigated. Twenty-eight adult mongrel dogs were divided into three groups that underwent the following treatments: antegrade perfusion (group 1, n = 9); retrograde perfusion alone (group 2, n = 11); or tetrograde perfusion with drugs (manuitol, thiopental sodium, and methylprednisolone; group 3, n = 8). After 90 minutes of cerebral perfusion at 20 degrees C of the pharyngeal temperature, evans blue (EB) was administered to check for disruptions of the blood-brain-barrier (BBB) and brain tissue water content was measured. Intracranial pressure after cerebral perfusion was markedly higher in group 2 than in group 1 (26.4 +/- 9.4 vs. 11.2 +/- 3.6 mmHg), and brain tissue water content was also significantly higher in group 2 than in group 1 (80.7 +/- 2.0 vs. 77.8 +/- 0.9%). These data suggested that brain edema was more prominent after retrograde perfusion than after antegrade perfusion. The extent of EB to brain tissue was greater in group 2 than in group 1 (169.8 +/- 97.7 vs. 54.7 +/- 31.5 micrograms/dl). The BBB was highly disrupted in group 2 and vasogenic edema appeared after retrograde cerebral perfusion. Maximum intracranial pressure, brain tissue water content and EB concentration were significantly lower in group 3 than in group 2, and did not differ significantly between group 3 and 1. Administration of pharmacologic agents suppressed edema formation and extravasation of EB. We conclude that 90 minutes of retrograde cerebral perfusion at 20 degrees C of the pharyngeal temperature causes brain edema and disrupts the BBB in a manner different from that associated with antegrade perfusion. Mannitol, thiopental sodium, and methylprednisolone prevent these phenomena, indicating that pharmacologic intervention may improve the safety of retrograde cerebral perfusion.

Total Aortic Arch Replacement with Open Stent-Grafting of Descending Thoracic Aorta for Chronic Type A Dissecting Aneurysm after Replacement of the Ascending Thoracic Aorta-A Case Report-

症例は74歳,女性.平成11年2月13日に急性A型大動脈解離の診断にて上行大動脈置換術を施行した.平成13年4月遠位弓部大動脈より左総腸骨動脈に及ぶ残存解離と胸部下行大動脈の拡大を指摘され手術適応とされた.手術は開放式ステントグラフティングを併用した弓部大動脈置換術を施行した.術後呼吸障害を合併したが,対麻痺の合併なく軽快退院した.

Open Surgical Repair for a Perigraft Leak After Endovascular Stent-Graft Emplacement of Descending Thoracic Aneurysm

Although transluminal stent-graft implantation is less invasive for treating an aneurysm in the thoracic descending aorta, this technique is not always successful. Here, we report two cases of a perigraft leak identified after stent-graft deployment, and complete occlusion of the leak could not be attained by additional stent-graft deployment. Open surgical repair using a stented graft was performed through a median sternotomy without opening the left pleura. This procedure should be considered as one of the less-invasive techniques for treating a perigraft leak after endovascular stent-graft emplacement.