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M Imamaki

Publications and source records attributed to M Imamaki.

34 records · Page 2Linked to original sources
PubMed1993

[Effect of retrograde cerebral perfusion in preserving cerebral function during circulatory arrest].

The efficacy of retrograde cerebral perfusion (RCP) method was evaluated in 26 patients who underwent aortic arch reconstruction. Surgical procedures were; ascending-proxymal arch replacement involving Bentall type procedures (17 cases), total arch replacement (4 cases), and distal arch replacement (5 cases). The RCP were performed through selective cannulation on the superior vena cava at 18.4 degrees C of the average rectal temperature. The perfusion pressure was 28.3 (+/- 5.9) cmH2O and flow was 360 (+/- 15.4) ml/min. RCP time was 74.1 (+/- 26.2) min. Twenty-four patients survived among 26 patients and 2 patients died after operation. Postoperative consciousness was confirmed in 25 patients. Postoperative neurological complications were 1) delayed arousal 5 cases, 2) delirium 3 cases, 3) respiratory disorders 5 cases, 4) double vision 2 cases, 5) cerebral infarction (CI) 1 case. These complications except-CI were resolved in early postoperative period. And regarding effective time period of RCP, incidence of neurological complications were significantly higher in cases which received RCP over 80 min. Therefore we consider that 80 min is a safety time period. In conclusion, RCP is a useful step for preserving the brain during the operation of graft replacement of aorta involving aortic arch.

Aortic Dissection↗
PubMed1993

[Effectiveness of continuous retrograde cerebral perfusion for surgical treatment of aneurysms of the aortic arch--comparison with antegrade cerebral perfusion].

Several methods have been used for an adjunct to perform operation of aortic arch aneurysms. However, their results were often not so reasonable. Recently retrograde cerebral perfusion was reported as a new adjunctive method. In our institute, for the past 6 and a half years from May 1985 to April 1992, 50 patients underwent reconstruction of the transverse aortic arch by using two methods of artificial cerebral perfusion. One method is continuous antegrade cerebral perfusion (ACP, for 32 patients), and the other is continuous retrograde cerebral perfusion (RCP, for 18 patients), each technique was combined with deep hypothermia (18-20 degrees C) and low flow perfusion (10-30 ml/kg/min) to lower half body performed from femoral artery. In our RCP circuit, an additional pump was used for cerebral perfusion to superior vena cava, but the circuit was much simpler than the circuit in ACP. We compared the two methods (ACP versus RCP) as regards to the following items and the results were showed in parentheses; hospital death (8/32, 25%: 2/18, 11%), respiratory complication (8.27, 30%: 3/18, 17%), neurological complication (7/29, 24%: 1/18, 5.5%), duration of extracorporeal circulation (306.8 +/- 74.5 min: 260.4 +/- 60.0 min), periods of pre-ECC in the operation (160.3 +/- 69.2 min: 117.7 +/- 35.3 min), duration of cerebral perfusion (113.6 +/- 45.4 min: 74.1 30.5 min) and amount of bleeding (3424 +/- 2881 ml: 1802 +/- 1291 ml). RCP has superior advantages in all of those in comparison with ACP. These results suggest that RCP is a useful adjunctive method for reconstruction of aortic arch with a low operative risk.

Adult↗
PubMed1993

[Recent advances of surgical treatment of aortic arch aneurysm using retrograde cerebral perfusion].

Between March 1985 and September 1992, 68 patients underwent the replacement of the arch aorta. To protect the brain we had used selective cerebral perfusion (SCP) in 33 cases, but since October 1990 we have used retrograde cerebral perfusion (RCP) in 35 cases. Compared with SCP, RCP decreased the incidences of cerebral infarction and irreversible cerebral complications from 27% to 4% (p < 0.01), and hospital mortality rate from 27% to 14%. However RCP over 80 minutes made complication of transient consciousness disturbance in 4 of 7 cases (57%). We measured cerebral blood flow (CBF) by transcranial Doppler at middle cerebral arteries in 7 cases. After RCP, CBF decreased between 50% and 10% and could not be detected in 3 cases. Reactive hyperemia occurred in all cases after RCP ended. RCP will increased circulatory arrest time by about 30 minutes according to our clinical data.

Aortic Dissection↗
PubMed1993

["Separate hypothermia" retrograde cerebral perfusion for repair of aortic arch].

We have developed a new technique of retrograde cerebral perfusion. To avoid the disadvantages by deep hypothermia, and to protect the brain for longer time, we perfused from SVC cannula with blood cooled at 10-15 degrees C, at the same time from femoral artery with blood cooled at 20-26 degrees C. From October 1991 to December 1992, 8 patients underwent surgical repair using this method. By this method, the cases of which cerebral perfusion time were 147, 134, 125, 119, 110 minutes, did not have neurological deficits.

Aged↗
PubMed1993

[Efficacy of myocardial preservation using HTK solution in continuous 120 min cross-clamping method--a comparative study with GIK method].

The aim of this study is to investigate the efficacy of HTK solution in the 120 minutes cross-clamping method in comparison with conventional intermittent cardioplegia using GIK solution. Fifty-four open heart surgery were performed with cardioplegic solution using either HTK solution (HTK) or GIK solution (GIK). In the HTK, HTK (3L) was infused for the initial dose and 1L was added every 60 min after 120 min of cross-clamping. In GIK, 1L of GIK solution was intermittently infused initially and then every 30 min together with continuous cold blood perfusion. The effect of two cardioplegic solution was evaluated by postoperative cardiac function (CI, %SF), released enzymes (CPK), histology and dosage of catecholamine. Postoperative CI was 3.67 +/- 0.76 in HTK, and 4.34 +/- 1.04 in GIK (NS). % SF was 26.0 +/- 5.26 in HTK and 25.6 +/- 0.76 in HTK, and 4.34 +/- 1.04 in GIK (NS). %SF was 26.0 +/- 5.26 in HTK and 25.6 +/- 9.2 in GIK (NS). The CK-MB (IU/dl) level after reperfusion was significantly decreased in HTK at 60 and 180 min after reperfusion. Histology at 60 min of ischemia revealed a significant increase of edema of mitochondria in GIK. Postoperative catecholamine dose was 2.65 +/- 1.3 in HTK and 10.3 +/- 3.4 in GIK (p < -0.01). PH of myocardium was well maintained around 7.4 during cross-clamping in HTK, however, it was decreased in GIK. In conclusion, The HTK method offers a reliable cardiac protection due to effective buffering using Histidine in comparison with GIK.

Cardioplegic Solutions↗
PubMed1993

[An arch and ascending replacement for aortic arch dissection by "separate hypothermia" retrograde cerebral perfusion].

We have developed a new technique of cerebral perfusion during operations on the aortic arch. The concept of this technique is as follows. A retrograde cerebral perfusion provides a relative long time to perform the distal aortic repair, and simplifies the operation. To avoid the disadvantages by deep hypothermia, we perfused from SVC cannula with blood cooled at 10-15 degrees C, from femoral artery with blood cooled at 20-26 degrees C. A successful case using this method is as follows. A 68-year-old man was referred to our hospital for aortic arch dissection. He underwent an operation 4 weeks after onset. Graft replacement of ascending aorta and aortic arch was performed under this method. We perfused blood from SVC cannula at an internal jugular vein pressure of 30 cmH2O, and SVC perfusion flow was 600 cc/min. By this separate hypothermia perfusion, the nasopharyngeal temperature is maintained about 15 degrees C, the rectal temperature is maintained 22-24 degrees C. The duration of cerebral perfusion from SVC cannula was 125 min, but prolonged emergence from anesthesia and neurological deficit were not seen.

Aged↗
PubMed1993

[A case report of surgical treatment for aortic valve papillary fibroelastoma].

A 71-year-old woman was referred to our hospital for aortic valve replacement because of the vegetation of aortic valve. She had transient right arm weakness and aphasia in November 1991. On two-dimensional echocardiogram, she was found to have a mobile, pedunculated mass attached to the non-coronary cusp of the aortic valve. At operation, multiple frond-like tumor measuring 7*7 mm was found attached to the free-edge of the non-coronary cusp of the aortic valve. The aortic valve with this tumor was excised and replaced with a 21-mm Carpentier-Edwards prosthesis. Microscopic sections revealed the typical findings of a papillary fibroelastoma. The patient's postoperative course was unremarkable.

Aged↗
PubMed1992

[A case report on the sliding commissuroplasty for mitral regurgitation due to posterior commissural chordal rupture].

We have performed a mitral valve reconstruction on a 31-year-old man who suffered from infective endocarditis four years ago. Severe mitral regurgitation and posterior commissural chordal rupture were noted. The mitral valve was repaired by Carpentier's sliding commissuroplasty and ring annuloplasty. The postoperative course was uneventful, and mitral regurgitation completely disappeared. It appears that Carpentier's sliding commissuroplasty is a superior new reconstructive technique for mitral regurgitation due to commissural chordal rupture.

Adult↗
PubMed1992

[A clinical assessment of efficacy in continuous retrograde cerebral perfusion method].

From November 1990 to June 1991, 8 patients underwent surgical repair using continuous retrograde cerebral perfusion (CRCP). We evaluated the effect of CRCP from these 8 cases. As a method of CRCP, we perfused with oxygenated blood from SVC canulae with a internal jugular vein pressure of 30-40 cmH2O. Simultaneously systemic perfusion from femoral arterial canulae was performed. At nasopharyngeal temperature of 15-21 degrees C, CRCP time was 46-115 minute. SVC perfusion flow was 280-900 ml/min, and femoral arterial perfusion flow was 450-1,200 ml/min. At 30 minute after starting CRCP, oxygen tension of the blood which was returned to aortic arch was 11-23 mmHg, whereas oxygen tension of the SVC perfusion blood was 210-398 mmHg. In only one patient, transient involuntary movement was seen after operation, but prolonged emergence from anesthesia was not seen. In conclusion, CRCP is considered as an useful method in the operation of the aortic arch.

Aorta, Thoracic↗
PubMed1992

[Classification of congenitally bicuspid aortic valve and its angiographic and surgical significance].

From January, 1978 to December, 1990, 85 patients with congenital bicuspid aortic valve underwent aortic valve replacements (AVR) with St. Jude Medical valve prosthesis. We classified congenital bicuspid aortic valve into four types. Type I (44.7%): Two cusps are situated right and left, a coronary artery arises from each related sinus of valsalva. Type II (22.4%): Type I + raphe in the right cusp. Type III (3.5%): one cusp is located anteriorly, the other posteriorly and both coronary arteries arise from anterior cusp. Type IV (29.4%): Type III + raphe in the anterior cusp. Regarding to preoperative diagnosis, aortic stenosis dominated in Type I (78.8%) and aortic regurgitation dominated in Type IV (72.0%). Implanted valve sizes were 22.2 +/- 1.8 (Type I), 23.4 +/- 1.6 (Type II) and 24.0 +/- 2.2 (Type IV). There was a significant difference between Type I and Type II, same as Type I and Type IV. Babb's method and outflow measurement method were utilized to predict the aortic annular size. However, both of them were not reliable for estimating the size of the aortic annulus in cases of aortic stenosis undergoing AVR with a 21 mm prosthesis.

Adolescent↗
PubMed1991

[A case report of chronic traumatic dissecting aneurysm of the thoracic aorta].

A 63-year-old male, who sustained a blunt chest trauma in a traffic accident, was referred to our hospital for his traumatic aneurysm. An operative repair was undertaken 3 months after the trauma. The descending aorta was dissected along 5 cm, and its diameter was about 6 cm. Graft replacement was performed under the left heart bypass by using the BioMedicus centrifugal pump. He is doing well 3 years after the operation.

Accidents, Traffic↗
PubMed1990

[Frozen blood from one closely related donor reduced complications of blood transfusion without adverse effects in the open-heart surgery].

We used frozen blood from one closely related donor in 24 patients (group I) who underwent open heart surgery for congenital heart disease, in order to reduce of complications from a large quantity of blood transfusion. Blood of 600-2200 ml was collected from the single donor and was kept frozen until the operation. Two conditions of the patients were instituted, (1) body weight less than or equal to 40 kg (2) the single donor is father or mother or a close relative. The group of these patients was compared with patients using frozen autologous blood (group II) and patients using banked blood (group III). In group I patients two times of decline of red blood cell counts (RBC), hematocrit (Ht), hemoglobin (Hb) and total protein (TP) were noticed. The first was the period during the cardio-pulmonary bypass. The second was the time about one week after the transfusion of frozen red cells. But degree of the decline was uneventful clinically. The increment of complications induced from the use of frozen red cells was not noticed, and there was no case of serum hepatitis in group I patients. We concluded that the open-heart surgery using frozen blood cells (single donor), if the application was appropriate, could be undergone safely and would be effective on reducing infection and reaction induced from blood transfusion.

Adolescent↗
PubMed1990

[Post-operative evaluation of a 17 mm diameter Björk-Shiley Monostrut prosthesis for aortic valve replacement--pressure gradient and effective valve area].

A 17 mm diameter Björk-Shiley Monostrut prosthesis was implanted in a 64-year-old female for aortic valve replacement in a semi-emergency. This valve was one of the smallest valves which were available in Japan. The patient was admitted because of severe hemolytic anemia and heart failure. Echocardiography showed regurgitation and calcification of Ionescu-Shiley tissue valve which was implanted 5 years ago. The patient's body surface area was 1.2 m2. Because of narrow aortic annulus, we could barely implant a 17 mm diameter Björk-Shiley Monostrut prosthesis. The valve function was examined by Brockenbrough method. During catheterization, the heart rate was 85 b/min and cardiac index was 3.00 l/min/m2. In these hemodynamic conditions, simultaneous measurements of aortic and left ventricular pressures revealed only 9 mmHg mean systolic pressure gradient. Similarly, 20 mmHg of pressure gradient across the implanted valve was obtained by Gorlin's formula. We could calculate that the effective orifice area of a 17 mm diameter Björk-Shiley Monostrut prosthesis was 1.0 cm2. Postoperative echocardiography demonstrated 42 mmHg systolic pressure gradient across this prosthesis by Doppler techniques, and left ventricular wall thickness was not decreased. To best our knowledges, this was the first case in which post-operative evaluation such a small prosthesis was measured.

Aortic Valve↗