PubMed Health⌕ Search

Biomedical subjects

Tetsuro Morota

Publications and source records attributed to Tetsuro Morota.

At least 19 recordsLinked to original sources
PubMed2006

A simple modification of 'David-V' aortic root reimplantation.

Valve-sparing aortic root reimplantation with creation of Dacron graft pseudosinuses is a popular and promising surgical choice for annuloaortic ectasia or ascending aortic aneurysm. We have developed a simple modification of the David-V technique, which facilitates free adjustment of the size of the new aortic annulus and the pseudosinus of each patient, as well as the creation of pseudosinuses of excellent shape, with only one Dacron graft.

Aorta↗
PubMed2006

Complete coverage of in situ aortograft by total omental pedicle flap as the most reliable treatment of aortoesophageal fistula.

Aortoesophageal fistula secondary to a thoracic aortic aneurysm is usually a fatal disease with few survivors reported previously. We encountered 2 consecutive patients who were treated successfully with esophagectomy and in situ aorta reconstruction using cryopreserved homograft that was wrapped completely with omental pedicle flap. For the construction of omental flap, the right gastroepiploic artery was resected at the root and all the vessels entering the greater curvature and the transverse colon were resected at the adherent edges. Because the gastroepiploic arcade is totally preserved, large amounts of omental tissue could be obtained, with an excellent blood supply mainly from the left gastroepiploic artery. This type of omental flap is highly mobile, easily transferred to the left hemithorax, and has enough volume to cover the in situ aortic graft completely including anastomosis lines. Thus, our omental coverage appears to be the most reliable method to prevent postoperative graft infection.

Aged↗
PubMed2006

Erythropoietin protects the central nervous system during prolonged hypothermic circulatory arrest: an experimental study in a canine model.

OBJECTIVE: Current data suggest that erythropoietin protects the brain and the spinal cord from ischemic and traumatic injury. In this study, we determined whether erythropoietin protects the central nervous system during prolonged hypothermic circulatory arrest in an experimental canine model. METHODS: Ten adult beagle dogs were randomly and intravenously injected with either 5000 U/kg recombinant human erythropoietin or normal saline. Each dog was then subjected to a cardiopulmonary bypass and 120 minutes of deep hypothermic circulatory arrest (18 degrees C). The level of tau proteins in the cerebrospinal fluid, a modified marker of neurologic deficit in dogs, and the histopathologic characteristics of the brains and spinal cords were then examined. RESULTS: The level of tau proteins was significantly lower in the erythropoietin-treated group than in the untreated group at 6 hours (20 +/- 12 vs 144 +/- 54 pg/mL; P = .036) and 12 hours (64 +/- 35 vs 478 +/- 103 pg/mL; P = .01) after the operation. The total Neurologic Deficit Score was 59 +/- 31 (0, normal; 500, brain death) in the erythropoietin-treated group, compared with 376 +/- 30 in the untreated group (P = .0117). Histopathologic examination revealed that ischemic neuronal changes and apoptosis in the hippocampus CA1 were significantly lower in the erythropoietin-treated group (P < .01 and P = .028, respectively). CONCLUSIONS: This study showed that erythropoietin protected the central nervous system during prolonged hypothermic circulatory arrest, partly by preventing both necrosis (ischemic neuronal changes) and apoptosis.

Animals↗
PubMed2006

Intermittent pressure augmentation during retrograde cerebral perfusion under moderate hypothermia provides adequate neuroprotection: an experimental study.

OBJECTIVE: For cerebral protection during aortic surgery, we introduced a novel retrograde cerebral perfusion method with intermittent pressure augmentation. We then assessed whether this novel method provides benefits similar to those provided by antegrade selective cerebral perfusion. METHODS: Eighteen dogs were randomly divided into 3 groups: the RCP-INT group, intermittent-retrograde cerebral perfusion at 15 mm Hg with intermittent pressure augmentation to 45 mm Hg (n = 6); the ASCP group, antegrade selective cerebral perfusion at a flow rate of 10 mL x kg(-1) x min(-1) (n = 6); and the sham group, no circulatory arrest (n = 6). Cooling (26 degrees C) with cardiopulmonary bypass and 60 minutes of circulatory arrest were performed in the RCP-INT and ASCP groups. The levels of tau protein in the cerebrospinal fluid and the diameters of the retinal vessels were measured. The neurologic deficit scores and the histopathologic damage scores of the brains were determined. RESULTS: The total postoperative tau protein levels (calculated as the area under the curve) did not differ significantly between the RCP-INT and ASCP groups (203 +/- 87 pg x mL(-1) x h vs 154 +/- 69 pg x mL(-1) x h, P = .95). The retinal vessels were effectively dilated at an augmented pressure of 45 mm Hg in the RCP-INT group. The total neurologic deficit score (0 = normal, 500 = brain death) and histopathologic damage score (0 = normal, 40 = worst) were not significantly different between the RCP-INT and ASCP groups (neurologic deficit score: 75 +/- 21 vs 70 +/- 21, P = .98; histopathologic damage score: 13.5 +/- 1.5 vs 14.2 +/- 1.3, P = .84). CONCLUSIONS: Intermittent augmented pressure dilated the cerebral vessels, allowing adequate blood supply without injuring the brain. This retrograde cerebral perfusion method provides adequate neuroprotection during moderate hypothermia.

Animals↗
PubMed2006

Retrograde cerebral perfusion with intermittent pressure augmentation provides adequate neuroprotection: diffusion- and perfusion-weighted magnetic resonance imaging study in an experimental canine model.

OBJECTIVE: Diffusion- and perfusion-weighted magnetic resonance imaging can identify ischemic brain injury in the hyperacute stage. For neuroprotection during thoracic aortic surgery, we developed a novel retrograde cerebral perfusion with intermittent pressure augmentation. The purpose of this study was to assess the efficiency of this novel method for neuroprotection in real time by using diffusion- and perfusion-weighted magnetic resonance imaging. METHODS: Sixteen beagle dogs were randomly divided into 4 groups: the antegrade selective cerebral perfusion group (n = 4; antegrade selective cerebral perfusion at a flow rate of 10 mL x kg(-1) x min(-1)); the intermittent retrograde cerebral perfusion group (n = 4; retrograde cerebral perfusion at a baseline pressure of 15 mm Hg with intermittent pressure augmentation to 45 mm Hg every 30 seconds); the conventional retrograde cerebral perfusion group (n = 4; conventional retrograde cerebral perfusion at a fixed pressure of 25 mm Hg); and the circulatory arrest group (n = 4; only circulatory arrest). Diffusion- and perfusion-weighted magnetic resonance images were acquired during each session of cerebral perfusion. Regions of interest were defined, and the apparent diffusion coefficient and relative regional cerebral blood volume were calculated in these regions of interest. Finally, the brain was evaluated for its histopathologic damage score. RESULTS: The best apparent diffusion coefficient values were observed in the intermittent retrograde cerebral perfusion group in all the regions of interest, although the relative regional cerebral blood volume values were mostly lower than those in the antegrade selective cerebral perfusion group. The total Histopathologic Damage Score (0, normal; 32, worst) in the intermittent retrograde cerebral perfusion group (8.0 +/- 0.6) was significantly lower than that in the conventional retrograde cerebral perfusion (17.5 +/- 1.7; P < .01) and circulatory arrest (25 +/- 1.0; P < 0.01) groups and was equivalent to that in the antegrade selective cerebral perfusion group (7.8 +/- 0.8; P = .9). CONCLUSION: Intermittent retrograde cerebral perfusion provides adequate neuroprotection by allowing high apparent diffusion coefficient values to be maintained.

Animals↗
PubMed2006

A surgical case of symptomatic coronary artery-pulmonary artery fistula.

We describe a 55-year-old female patient with multiple plexiform coronary artery-pulmonary artery fistulas, who presented with ischemic episodes accompanying an inversion of T wave on an electrocardiogram even though it was a small shunt size. The surgical procedure involved closure of the openings of the fistulas from inside the pulmonary trunk using cardiopulmonary bypass with additional ligations. Postoperative coronary angiogram revealed complete interruption of the coronary artery-pulmonary trunk fistulas resulting in complete resolution of the patient's chest symptoms.

Angina Pectoris↗
PubMed2005

Management of infected grafts and aneurysms of the aorta.

Seventeen patients treated for infected grafts (11/17) or aneurysms (6/17) of the aorta between 1998 and 2003 were reviewed to evaluate our experience with aortic infection. The causative organisms were identified in 12 patients (71%), with 5 (29%) having methicillin-resistant Staphylococcus aureus. A periaortic abscess occurred in eight patients, and all of them were associated with infected grafts. Surgical treatment included cryopreserved allograft replacement in eight patients, prosthetic graft replacement in four patients, and drainage with or without omental wrapping in five patients. One patient was still hospitalized at the end of the study period. Five patients with infected grafts died after the operation during the initial hospitalization. No early mortality occurred in the aneurysm group. The early mortality rate was 31% for all patients, 50% for the graft group, and 63% for patients with a periaortie abscess. Another patient with an infected aneurysm died of arrhythmia after discharge from the initial hospitalization, Ten patients are still alive without evidence of reinfection. The early mortality rate for patients with infected aortic grafts is higher than that for those with infected aneurysms, especially when a periaortic abscess accompanies them. However, the late outcome is favorable, with no reinfection or late treatment-related deaths.

Abscess↗
PubMed2005

Surgical treatment of atypical aortic coarctation complicating Takayasu's arteritis--experience with 33 cases over 44 years.

PURPOSE: This study was conducted to evaluate the long-term outcomes of surgical treatment for atypical aortic coarctation due to Takayasu's arteritis and to elucidate the factors that affected outcome. METHODS: The outcomes of surgical treatment for atypical aortic coarctation complicating Takayasu's arteritis in 33 consecutive patients over the previous 44 years at our institution were reviewed retrospectively. Preoperatively, 29 patients had coarctation proximal to the renal arteries and hypertension in the upper half of the body. Four hospital deaths occurred, and the remaining 29 patients were followed from 0.5 to 42.0 years (median, 17.9 years). The impacts of several risk factors on survival as well as cardiac and vascular events were analyzed. RESULTS: Among 27 initial survivors who had hypertension preoperatively, 15 did not show normalization of blood pressure. The overall cumulative survival and event-free survival rate at 20 years were 62.3% and 58.4%, respectively. Serious long-term complications were anastomotic aneurysms, congestive heart failure, cerebrovascular accident, graft deterioration, abdominal aortic aneurysms, and renal failure. Among several risk factors analyzed, only the presence of postoperative hypertension had an effect on event-free survival. CONCLUSIONS: The long-term survival after surgery for atypical aortic coarctation was satisfactory. However, our study showed that complications associated with cardiovascular system or the operation could occur at any time after surgery; thus, life-long follow-up is mandatory. Further, the absence of normalization of blood pressure after surgery was a poor prognostic factor. Our results demonstrate the need for an intimate preoperative evaluation of renal and carotid artery lesions, which often coexist and may also cause secondary hypertension, to fully manage hypertension by surgery.

Adolescent↗
PubMed2005

Is the guideline the cause of structural failure in current polyester vascular prostheses? An experimental study.

To evaluate the impact of the guideline on the structural failure of current polyester vascular prostheses, we studied seven unsealed polyester vascular prostheses. An accelerated time test was used for assessing degradation of polymeric medical materials at pH 7.4 in phosphate buffer at a temperature of 95 degrees C. Probe burst strength was determined on the guideline and on standard parts of the prostheses during the accelerated time test. Weight-average molecular weights of the guideline and of the standard parts in all knitted grafts during the accelerated time test were measured. The guideline was significantly weaker than the standard parts in most prostheses. The guideline had significantly lower values of weight-average molecular weights than the standard parts in most knitted grafts. This study showed that guideline degeneration was one factor responsible for the structural failure of some current polyester vascular prostheses.

Blood Vessel Prosthesis↗
PubMed2005

Altered patterns of gene expression specific to thoracic aortic aneurysms: microarray analysis of surgically resected specimens.

Changes in the expression levels of several genes have been described in aortic aneurysm specimens, however, the spectrum of diverse molecular alterations remains to be elucidated. We attempted to identify key molecules that modulate the pathogenesis of aortic aneurysm, using a complimentary DNA microarray carrying approximately 13,000 human genes. Segments of thoracic aortic aneurysms (TAA) and adjacent normal thoracic aortic tissues without aneurysmal changes (NTA) were obtained from 20 patients undergoing graft surgery. RNA obtained from five pairs of TAA and NTA samples was compared to determine aneurysm-specific alterations using microarray. Further, the expression levels of several genes of interest were verified in the remaining specimens by real-time reverse transcription-polymerase chain reaction (RT-PCR). In microarray assays, several types of the matrix metalloproteinases were upregulated as reported previously. Also, 220 genes suggested to be involved in protein degradation, inflammation, apoptosis, stress response, intracellular signaling, and other processes were significantly upregulated. Many of these genes have not been previously implicated in cardiovascular disease. The real time RT-PCR independently confirmed that the expression levels of MMP-2, MMP-9, ADAMTS-1, and caspase 4 were consistently increased in TAA. The results indicate that many genes are involved in a complicated manner in the pathogenesis of TAA. Investigation of these genes will help clarify the pathogenesis of this disease, and may lead to the discovery of novel therapeutic targets.

ADAM Proteins↗
PubMed2004

Successful repair of graft failure and abdominal aortic aneurysm following thoraco-abdominal bypass for atypical aortic coarctation.

A 54-year-old woman, who underwent descendo-abdominal aortic bypass grafting for atypical aortic coarctation complicated with Takayasu's arteritis 37 years previously, was referred to our hospital for treatment of a pseudoaneurysm due to rupture of the graft. Preoperative computed tomography scan also demonstrated an abdominal aortic aneurysm. First, an endovascular stent-graft repair of the pseudoaneurysm was performed, then the abdominal aortic aneurysm was repaired with the aid of cardiopulmonary bypass. Proper surgical planning was important to treat this rare development accompanied by aberrant circulation.

Aortic Aneurysm, Abdominal↗
PubMed2004

Thrombus originating from frayed distal edge of an aortic stent-graft.

An 87-year-old woman who had undergone a stent-graft repair of a descending aortic aneurysm had additional stent-graft implantation for endoleak. The postoperative course was eventful reflecting her preexisting multiple organ disorder, and despite intensive treatment over a span of 2 months, she died of disseminated intravascular coagulation due to intestinal ischemia. Autopsy revealed a thrombus originating from the frayed distal edge of the graft. Although the relation between intestinal ischemia and the thrombus remains to be proven, this is considered a vital finding.

Aged↗
PubMed2004

[Acute type A aortic dissection].

BACKGROUND: Current surgical results for acute type A aortic dissection has been getting better, though the mortality rate still remains high, up to 10-15% in Japan. Our strategy consists of #1 make the most use of echography for better understanding of hemodynamics; #2 the extent of replacement depends on the site of initial entry; #3 deep hypothermic circulatory arrest and retrograde cerebral perfusion for brain protection. PATIENTS AND METHODS: Between January 2000 and December 2003, 45 consecutive patients were treated. Twelve of them had extended replacement of the arch, and 3 had simultaneous root replacement by means of a composite graft. RESULTS: In hospital mortality was 11% (5 patients). The cause of death was serious organ malperfusion, which had been developed preoperatively, in all patients but 1 who suffered from thoracic aortic obstruction due to newly developed type B aortic dissection. CONCLUSIONS: The determinant of surgical mortality in patients with acute type A aortic dissection is the presence of serious organ malperfusion. Rapid diagnosis and less invasive treatment for malperfusion is the key to improve the results.

Acute Disease↗
PubMed2003

Rupture of a small fusiform thoracic aortic aneurysm.

We report a case of ruptured aortic aneurysm of the distal aortic arch. This aneurysm was fusiform and only 4.0 cm in maximum diameter. Emergency total aortic arch replacement was successful. Rupture of a thoracic aortic aneurysm of this shape and size is possible but extremely rare.

Aged↗
PubMed2003

Epicardial pulmonary vein isolation by cryoablation as concomitant cardiac operation to treat nonvalvular atrial fibrillation.

Since Haïssagere and colleagues reported that a rapid firing focus in or close to the pulmonary veins could be the cause of atrial fibrillation, a transcutaneous catheter technique directed at isolating these foci has been developed. How should patients with nonvalvular atrial fibrillation who require cardiac operation be managed? We developed an epicardial technique that uses cryoablation to isolate the left atrial posterior wall and pulmonary veins and used it to treat a patient. Because cryoablation is achieved epicardially, the technique does not require atriotomy and does not prolong aortic cross-clamp time. Isolation of the left atrium was confirmed by electrophyscologic studies, and the patient remains in sinus rhythm 16 months after operation. This concomitant procedure allows treatment of patients with nonvalvular atrial fibrillation.

Aged↗
PubMed2003

Recurrent embolism caused by floating thrombus originating from the ligamentum arteriosum.

Few patients with an embolism derived from apparently normal thoracic aorta with no other disease have been reported. We were presented with a case of a floating thrombus originating from the ligamentum arteriosum that caused multiple embolic episodes in the bilateral common iliac and superior mesenteric arteries. From our findings, we recommend a surgical approach for a floating thrombus in the aorta to prevent further embolism.

Adult↗
PubMed2003

Emergent pulmonary thromboendarterectomy with percutaneous cardiopulmonary support system for chronic thromboembolic pulmonary hypertension.

Pulmonary thromboendarterectomy offers a comparatively low surgical mortality rate with appropriate patient selection. However, the operative mortality in patients with high pulmonary vascular resistance or severe pulmonary hypertension and subsequent right ventricular failure is poor. We report an unusual case that survived an emergent pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension with right ventricular failure.

Adult↗