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Papers by Soichiro Kitamura
Asaio Journal, Mar 1, 2004
Artificial Organs, 1999
We have been developing an electrohydraulic total artificial heart system. The system comprises a... more We have been developing an electrohydraulic total artificial heart system. The system comprises an intrathoracic pumping unit composed of diaphragm type ellipsoidal blood pumps and an energy converter in addition to an electronics unit. The in vivo performance of the pumping unit was evaluated in a series of animal implantations with 3 calves weighing 62–85 kg. An interatrial shunt 4.5 mm in diameter was made in the atrial septum to compensate left‐right imbalance. Two calves died early postoperatively, one of external controller power failure and the other of interatrial shunt stenosis due to thrombus formation. One calf, however, survived over 10 days under stable circulatory conditions. No abnormality was found in the oxygen metabolic condition or in major organ functions. The generation and dissipation of heat from the device was acceptable. This animal died of device malfunction caused by energy converter bearing breakdown. The device demonstrated a good anatomic fit without co...
JSME International Journal Series C, 2004
A new method using ultrasound sensors to detect the diaphragm position of a ventricular assist de... more A new method using ultrasound sensors to detect the diaphragm position of a ventricular assist device (VAD) was proposed. Two small ultrasound sensors of 2.4 mm diameter were attached to the outside surface of blood chamber of a pneumatic VAD. The receiving crystal received the ultrasound from the transmitting crystal reflected by the diaphragm. The diaphragm position was calculated by using geometric relation among two sensors and ultrasound propagation time. Validity of this method was evaluated in a mock circulation test under various driving conditions of VAD by comparing the ultrasound signals with driving pressure waveforms. The ultrasound signals could detect full-fill (FF) and full-eject (FE) status shortly before the spikes appeared on pressure waves, which are currently available to detect FE and FF but accompanies excessive extension of the diaphragm. This method would be helpful to avoid overloading of diaphragm. Linear correlation was observed between the output from VAD and blood volume calculated from the change of diaphragm position multiplied by the heart rate. This monitoring method of diaphragm of a VAD was proven to have advantages over the current method toward better control of a pneumatic VAD.
The Journal of the Japanese Association for Chest Surgery
The Journal of the Japanese Association for Chest Surgery
自然気胸に対する胸腔鏡下手術における術後再発およびその予防法について検討した.1992年から1997年3月までに胸腔鏡下に手術を施行した自然気胸は140例で, 9例 (6.4%) に術後再発を認... more 自然気胸に対する胸腔鏡下手術における術後再発およびその予防法について検討した.1992年から1997年3月までに胸腔鏡下に手術を施行した自然気胸は140例で, 9例 (6.4%) に術後再発を認めた.再手術は6例に対し行った.うち3例に前回の staple がブラ壁にかかっているのが認められ, ブラ壁の取り残しと考えられた.2例はブラの見落としあるいはブラの新生が考えられた.手術施行時期を前期2年とそれ以降の後期に分けると, 前期2年間は再発率が15%と高かったが, 後期は3%に有意に低下した (p<0.05).手術手技の習熟度の指標としての術後の肺瘻の発生率は後期に有意に少なく (p<0.05), 術後の肺瘻別での再発率は術後肺瘻を認めなかった群で有意に低かった (p<0.01).以上より, 術後再発は手術手技の習熟により減少できると思われた.さらに, 術式別の再発率はブラ切除に胸膜擦過を施行した群で有意に低く (p<0.01), 胸膜擦過による癒着療法も再発予防に有用な手段の一つと考えた.
Children
As an acquired ischemic heart disease in childhood, coronary-artery disease caused by Kawasaki di... more As an acquired ischemic heart disease in childhood, coronary-artery disease caused by Kawasaki disease (KD) has been known worldwide since the mid-1970s. KD patients who develop coronary-artery obstructive disease often need revascularization some time in their life. Coronary-artery revascularization for KD coronary lesions can be done with the surgical coronary-artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) procedures. However, the characteristics of coronary-arterial lesions caused by KD significantly differ from atherosclerotic coronary disease in adults. Therefore, it is much more difficult to determine the optimal time and selection of a coronary-artery revascularization procedure for KD sequelae. CABG using the internal thoracic artery has been accepted as a very useful and beneficial procedure since the mid-1980s, even in small children. Although the use of PCI in the late period can be effective in some adolescent and adult patients, the small ves...
The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation, 2018
The Jarvik 2000 ventricular assist device features a miniaturized intraventricular pump and an in... more The Jarvik 2000 ventricular assist device features a miniaturized intraventricular pump and an intermittent low-speed function that facilitates aortic valve opening. Despite its long history, little is known about the Jarvik device with regard to post-implantation outcomes. Prospectively collected data from 13 participating hospitals were extracted from the Japanese Registry for Mechanically Assisted Circulatory Support database to analyze mortality, morbidity and de-novo aortic regurgitation. Data on 83 patients who underwent implantation of the Jarvik 2000 were reviewed. Median support duration was 191 (maximum 758) days. All recipients underwent implantation as a bridge to transplantation. Overall survival proportions at 1 and 2 years were 85.0% and 79.3%, respectively. Nine patients were in INTERMACS Level 1, and 28 patients were on mechanical circulatory support at the time of implantation. Causes of death included stroke, infection and device malfunction. Three patients had th...
Proceedings of the Japan Academy. Series B, Physical and biological sciences, 2018
Prior to the 1970s, pediatric coronary artery bypass surgery (PCABS) was seldomly performed due t... more Prior to the 1970s, pediatric coronary artery bypass surgery (PCABS) was seldomly performed due to the lack of compelling surgical indications. The advent of coronary sequelae secondary to Kawasaki disease (KD) and the occurrence of coronary artery complications due to newly developed procedures, such as the arterial switch operation and early repair for intrinsic congenital coronary malformations, necessitated the development of PCABS. Because children grow rapidly and their life expectancy is very long, with increasing exercise capability requirements, the strategy for PCABS should differ from that for bypass surgery in adults. PCABS utilizing unilateral and bilateral internal thoracic arteries (ITA) has become the most reliable surgical method for children because of the distinct structure of ITAs being resistant to KD, growth potential according to the child's somatic growth and long-term patency without wall degeneration. This operation utilizing ITA grafts is now being per...
Vascular Surgery
In patients with arterial occlusion or stenosis of the lower extremity due to arteriosclerosis ob... more In patients with arterial occlusion or stenosis of the lower extremity due to arteriosclerosis obliterans (ASO), vascular lumen was angioscopically observed immediately after transluminal balloon angioplasty (TBA). Five major findings were observed and classified: (1) abrasion of the intima, (2) irregularity of the lumen due to poor expansion, (3) laceration of the wall, (4) mural thrombus, and (5) intraluminally protruding calcification. The degree of each finding was scored with a 3-grade scale (0, 1, or 2). In analysis of the relationship between angioscopic scoring and long-term vascular patency, when initial scores were high, decreased patency was seen in the early (within six months) and late (after six months) (p<0.05) postoperative periods (p<0.01). In patients in whom total scores were over 5, the vascular patency rate was markedly low (11 % and 0% in the early and late postoperative periods, respectively) (ρ<0.01). These results indicate the usefulness of angiosco...
The Journal of Heart and Lung Transplantation
In Japan, ventricular assist devices (VADs) have been used for patients with severe heart failure... more In Japan, ventricular assist devices (VADs) have been used for patients with severe heart failure as a bridge to transplantation (BTT) since 1992. However, it was not until 1997, when the Organ Transplant Law was enacted, that medical devices received approval by the national health insurance system for that use. To encourage research and development of innovative medical devices, the Pharmaceuticals and Medical Devices Agency has established a public-private partnership in collaboration with academic societies, hospitals and manufacturers. The Japanese registry for Mechanically Assisted Circulatory Support (J-MACS) is a prospective registry designed to be harmonized with the Interagency Registry of Mechanically Assisted Circulatory Support (INTERMACS). Participation in J-MACS is mandatory for device manufacturers to meet the conditions of approval as well as for hospitals to obtain authorization for reimbursement from the national health insurance system. From June 2010 to April 2015, 476 patients were registered at 31 hospitals. Of these, analysis of primary VAD patients (n = 332) revealed that their overall 360-day survival was 91% (implantable 93%, extracorporeal 84%). This initial report from J-MACS focuses on patients&amp;amp;amp;#39; demographics, device types, survival, competing outcomes, adverse events and successful examples of system failure detection.
Circulation, Oct 28, 2008
Circulation Journal Official Journal of the Japanese Circulation Society, Mar 1, 2004
Circulation, Oct 31, 2007
Circulation Journal Official Journal of the Japanese Circulation Society, Mar 1, 2005
Circulation, Oct 31, 2006
Japanese Circulation Journal, Aug 20, 1977
Asaio Journal, Mar 1, 2004
Artificial Organs, 1999
We have been developing an electrohydraulic total artificial heart system. The system comprises a... more We have been developing an electrohydraulic total artificial heart system. The system comprises an intrathoracic pumping unit composed of diaphragm type ellipsoidal blood pumps and an energy converter in addition to an electronics unit. The in vivo performance of the pumping unit was evaluated in a series of animal implantations with 3 calves weighing 62–85 kg. An interatrial shunt 4.5 mm in diameter was made in the atrial septum to compensate left‐right imbalance. Two calves died early postoperatively, one of external controller power failure and the other of interatrial shunt stenosis due to thrombus formation. One calf, however, survived over 10 days under stable circulatory conditions. No abnormality was found in the oxygen metabolic condition or in major organ functions. The generation and dissipation of heat from the device was acceptable. This animal died of device malfunction caused by energy converter bearing breakdown. The device demonstrated a good anatomic fit without co...
JSME International Journal Series C, 2004
A new method using ultrasound sensors to detect the diaphragm position of a ventricular assist de... more A new method using ultrasound sensors to detect the diaphragm position of a ventricular assist device (VAD) was proposed. Two small ultrasound sensors of 2.4 mm diameter were attached to the outside surface of blood chamber of a pneumatic VAD. The receiving crystal received the ultrasound from the transmitting crystal reflected by the diaphragm. The diaphragm position was calculated by using geometric relation among two sensors and ultrasound propagation time. Validity of this method was evaluated in a mock circulation test under various driving conditions of VAD by comparing the ultrasound signals with driving pressure waveforms. The ultrasound signals could detect full-fill (FF) and full-eject (FE) status shortly before the spikes appeared on pressure waves, which are currently available to detect FE and FF but accompanies excessive extension of the diaphragm. This method would be helpful to avoid overloading of diaphragm. Linear correlation was observed between the output from VAD and blood volume calculated from the change of diaphragm position multiplied by the heart rate. This monitoring method of diaphragm of a VAD was proven to have advantages over the current method toward better control of a pneumatic VAD.
The Journal of the Japanese Association for Chest Surgery
The Journal of the Japanese Association for Chest Surgery
自然気胸に対する胸腔鏡下手術における術後再発およびその予防法について検討した.1992年から1997年3月までに胸腔鏡下に手術を施行した自然気胸は140例で, 9例 (6.4%) に術後再発を認... more 自然気胸に対する胸腔鏡下手術における術後再発およびその予防法について検討した.1992年から1997年3月までに胸腔鏡下に手術を施行した自然気胸は140例で, 9例 (6.4%) に術後再発を認めた.再手術は6例に対し行った.うち3例に前回の staple がブラ壁にかかっているのが認められ, ブラ壁の取り残しと考えられた.2例はブラの見落としあるいはブラの新生が考えられた.手術施行時期を前期2年とそれ以降の後期に分けると, 前期2年間は再発率が15%と高かったが, 後期は3%に有意に低下した (p<0.05).手術手技の習熟度の指標としての術後の肺瘻の発生率は後期に有意に少なく (p<0.05), 術後の肺瘻別での再発率は術後肺瘻を認めなかった群で有意に低かった (p<0.01).以上より, 術後再発は手術手技の習熟により減少できると思われた.さらに, 術式別の再発率はブラ切除に胸膜擦過を施行した群で有意に低く (p<0.01), 胸膜擦過による癒着療法も再発予防に有用な手段の一つと考えた.
Children
As an acquired ischemic heart disease in childhood, coronary-artery disease caused by Kawasaki di... more As an acquired ischemic heart disease in childhood, coronary-artery disease caused by Kawasaki disease (KD) has been known worldwide since the mid-1970s. KD patients who develop coronary-artery obstructive disease often need revascularization some time in their life. Coronary-artery revascularization for KD coronary lesions can be done with the surgical coronary-artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) procedures. However, the characteristics of coronary-arterial lesions caused by KD significantly differ from atherosclerotic coronary disease in adults. Therefore, it is much more difficult to determine the optimal time and selection of a coronary-artery revascularization procedure for KD sequelae. CABG using the internal thoracic artery has been accepted as a very useful and beneficial procedure since the mid-1980s, even in small children. Although the use of PCI in the late period can be effective in some adolescent and adult patients, the small ves...
The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation, 2018
The Jarvik 2000 ventricular assist device features a miniaturized intraventricular pump and an in... more The Jarvik 2000 ventricular assist device features a miniaturized intraventricular pump and an intermittent low-speed function that facilitates aortic valve opening. Despite its long history, little is known about the Jarvik device with regard to post-implantation outcomes. Prospectively collected data from 13 participating hospitals were extracted from the Japanese Registry for Mechanically Assisted Circulatory Support database to analyze mortality, morbidity and de-novo aortic regurgitation. Data on 83 patients who underwent implantation of the Jarvik 2000 were reviewed. Median support duration was 191 (maximum 758) days. All recipients underwent implantation as a bridge to transplantation. Overall survival proportions at 1 and 2 years were 85.0% and 79.3%, respectively. Nine patients were in INTERMACS Level 1, and 28 patients were on mechanical circulatory support at the time of implantation. Causes of death included stroke, infection and device malfunction. Three patients had th...
Proceedings of the Japan Academy. Series B, Physical and biological sciences, 2018
Prior to the 1970s, pediatric coronary artery bypass surgery (PCABS) was seldomly performed due t... more Prior to the 1970s, pediatric coronary artery bypass surgery (PCABS) was seldomly performed due to the lack of compelling surgical indications. The advent of coronary sequelae secondary to Kawasaki disease (KD) and the occurrence of coronary artery complications due to newly developed procedures, such as the arterial switch operation and early repair for intrinsic congenital coronary malformations, necessitated the development of PCABS. Because children grow rapidly and their life expectancy is very long, with increasing exercise capability requirements, the strategy for PCABS should differ from that for bypass surgery in adults. PCABS utilizing unilateral and bilateral internal thoracic arteries (ITA) has become the most reliable surgical method for children because of the distinct structure of ITAs being resistant to KD, growth potential according to the child's somatic growth and long-term patency without wall degeneration. This operation utilizing ITA grafts is now being per...
Vascular Surgery
In patients with arterial occlusion or stenosis of the lower extremity due to arteriosclerosis ob... more In patients with arterial occlusion or stenosis of the lower extremity due to arteriosclerosis obliterans (ASO), vascular lumen was angioscopically observed immediately after transluminal balloon angioplasty (TBA). Five major findings were observed and classified: (1) abrasion of the intima, (2) irregularity of the lumen due to poor expansion, (3) laceration of the wall, (4) mural thrombus, and (5) intraluminally protruding calcification. The degree of each finding was scored with a 3-grade scale (0, 1, or 2). In analysis of the relationship between angioscopic scoring and long-term vascular patency, when initial scores were high, decreased patency was seen in the early (within six months) and late (after six months) (p<0.05) postoperative periods (p<0.01). In patients in whom total scores were over 5, the vascular patency rate was markedly low (11 % and 0% in the early and late postoperative periods, respectively) (ρ<0.01). These results indicate the usefulness of angiosco...
The Journal of Heart and Lung Transplantation
In Japan, ventricular assist devices (VADs) have been used for patients with severe heart failure... more In Japan, ventricular assist devices (VADs) have been used for patients with severe heart failure as a bridge to transplantation (BTT) since 1992. However, it was not until 1997, when the Organ Transplant Law was enacted, that medical devices received approval by the national health insurance system for that use. To encourage research and development of innovative medical devices, the Pharmaceuticals and Medical Devices Agency has established a public-private partnership in collaboration with academic societies, hospitals and manufacturers. The Japanese registry for Mechanically Assisted Circulatory Support (J-MACS) is a prospective registry designed to be harmonized with the Interagency Registry of Mechanically Assisted Circulatory Support (INTERMACS). Participation in J-MACS is mandatory for device manufacturers to meet the conditions of approval as well as for hospitals to obtain authorization for reimbursement from the national health insurance system. From June 2010 to April 2015, 476 patients were registered at 31 hospitals. Of these, analysis of primary VAD patients (n = 332) revealed that their overall 360-day survival was 91% (implantable 93%, extracorporeal 84%). This initial report from J-MACS focuses on patients&amp;amp;amp;#39; demographics, device types, survival, competing outcomes, adverse events and successful examples of system failure detection.
Circulation, Oct 28, 2008
Circulation Journal Official Journal of the Japanese Circulation Society, Mar 1, 2004
Circulation, Oct 31, 2007
Circulation Journal Official Journal of the Japanese Circulation Society, Mar 1, 2005
Circulation, Oct 31, 2006
Japanese Circulation Journal, Aug 20, 1977