Biomedical subjects

Kenji Matsuzaki

Publications and source records attributed to Kenji Matsuzaki.

At least 19 recordsLinked to original sources

PubMed2006

Heparin reduction with the use of cardiotomy suction is associated with hyperfibrinolysis during distal aortic perfusion with a heparin-coated semi-closed cardiopulmonary bypass system.

We sought to elucidate the effects of different anticoagulation levels and the use of cardiotomy suction on the postoperative coagulatory and fibrinolytic systems in patients undergoing distal aortic perfusion using a fully heparin-coated (semi-)closed cardiopulmonary bypass (CPB) system incorporating a soft reservoir bag. Thirty-two patients were divided into two groups: those who underwent cardiotomy suction (S group, 18 patients) and those who did not (N group, 14 patients). We administered 1-2 mg/kg heparin in the S group, which achieved an activated clotting time (ACT) of 345 +/- 71 s. In the N group, we administered 0.7-1 mg/kg heparin, which achieved an ACT of 297 +/- 52 s. Data on platelet counts and serum levels of fibrinogen, antithrombin III, D-dimer, and fibrin degradation products (FDP) were collected, and factors influencing these variables were analyzed by multiple regression analysis. Both the patient group and the initial ACT level were independent factors influencing postoperative levels of FDP and D-dimer, whereas peak ACT level and the use of selective visceral/renal shunt/perfusion, but not the patient group, were independent factors influencing the postoperative platelet counts. In the S group, a significant inverse correlation was found between the ACT and levels of FDP or D-dimer, whereas no correlation was found in the N group. The use of cardiotomy suction was associated with elevated FDP and D-dimer levels even when a fully heparin-coated semi-closed CPB system was used. Lower ACT levels with the use of cardiotomy suction were associated with higher FDP and D-dimer levels, whereas such a relationship did not exist when cardiotomy suction was not used.

Aged↗

PubMed2006

Spontaneous perigraft hematoma suggesting transgraft hemorrhage seven years after thoracic aortic replacement with a Dacron graft.

As a previously unrecognized late graft-related complication, we report a case of spontaneous perigraft hemorrhage, which was evidenced by contrast extravasation on computed tomographic scan seven years after thoracic aortic replacement with a knitted Dacron graft. There was no anastomotic problem or graft tear, and the hematoma seemed to result from transgraft hemorrhage. Inadequate graft healing and use of a knitted graft in the thoracic aorta seem underlying. Surgeons should be aware of this complication and we advocate careful long-term follow-up.

Aged↗

PubMed2006

Percutaneous mesenteric stenting followed by laparoscopic exploration for visceral malperfusion in acute type B aortic dissection.

A 55-year-old man underwent percutaneous mesenteric and left renal stenting for malperfusion in acute type B aortic dissection. Laparoscopic exploration was performed immediately after percutaneous revascularization to ensure the integrity of the abdominal viscera. Because the diagnosis of mesenteric infarction may sometimes be difficult and its delay can be fatal, we advocate laparoscopic exploration as a mini-invasive method after percutaneous management of visceral malperfusion, if the integrity of the abdominal viscera needs to be verified.

Aortic Dissection↗

PubMed2006

Proximal aortic replacement with ascending-descending bypass for a diffuse aneurysm: report of a case.

We performed successful ascending-arch aortic replacement and concomitant ascending-to-descending aorta bypass with exclusion of a descending thoracic aneurysm, via median sternotomy, for a ruptured aortic aneurysm involving the entire thoracic aorta. The patient was an 80-year-old man with cardiopulmonary dysfunction and a history of lung tuberculosis. This operation, which has been used for complex descending thoracic aortic lesions such as recoarctation, is a feasible option for a diffuse thoracic aortic aneurysm when single-stage repair is mandatory.

Aged, 80 and over↗

PubMed2006

Extensive deployment of the stented elephant trunk is associated with an increased risk of spinal cord injury.

OBJECTIVE: Thoracic aortic aneurysm repair with the stented elephant trunk technique seems to be associated with an increased risk of spinal cord injury. We investigated whether severe atherosclerosis of the distal landing zone or extensive deployment of the stented elephant trunk is associated with increased risk of spinal cord injury. METHODS: Twenty-five patients underwent thoracic aortic aneurysm repair with the stented elephant trunk technique. The study population included 19 men and had a mean age of 73 +/- 7 years. All patients underwent a median sternotomy with cardiopulmonary bypass and selective cerebral perfusion. The elephant trunk was fixed with a Z-stent distal to the aneurysm during hypothermic circulatory arrest. Thirteen patients underwent concomitant total aortic arch replacement. RESULTS: Six (24%) patients had spinal cord injury. The presence of severe atherosclerosis at the distal landing zone demonstrated a tendency to increase the incidence of spinal cord injury (36% vs 9%, P = .1218). More distal deployment of the stented elephant trunk was significantly associated with increased risk of spinal cord injury (T8.0 +/- 0.6 vs T6.5 +/- 1.1, P = .0043). Univariate logistic regression analysis identified a history of abdominal aortic aneurysm repair (P = .0296) and the vertebral level of the distal landing zone (P = .0249) as significant independent risk factors for spinal cord injury, and only the latter was significant in multivariate analysis (P = .0396). The combination of a distal landing zone of T7 or greater and a history of abdominal aortic aneurysm repair was the strongest predictor for spinal cord injury (71% vs 6%, P = .0047). CONCLUSIONS: Spinal cord injury after stented elephant trunk deployment might be related to occlusion of the excessive intercostal arteries or thromboembolism. Patients with a history of abdominal aortic aneurysm repair who require extensive deployment of the stented elephant trunk seem to be at a higher risk for spinal cord injury.

Aged↗

PubMed2006

[Reconstruction of neck vessels in endovascular repair of aortic arch aneurysms].

We report 6 cases of aortic arch aneurysms necessitating reconstruction of the neck vessel during stent-graft (SG) placement. All patients were male and their average age was 75 years. The proximal landing zone was zone 0 in 2, zone 1 in 2, and zone 2 in 2 patients. The left subclavian artery (LSCA) was revascularized in every case; using left common carotid artery (LCCA)-LSCA bypass in 3, axillo-axillary artery bypass in 2, and LSCA transposition in 1. Prophylactic LCCA revascularization was done in 2 in which obstruction of LCCA by SG was anticipated. The proximal portion of LSCA from the origin of the vertebral artery was ligated in 3, and divided in 1. Two types of SG were used; Z stent in 1 and Matsui-Kitamura stent in 5. There was no hospital death or perioperative stroke. In the patient with Z stent, SG could not be deployed because of kinking of the delivery system. This patient subsequently underwent surgical SG placement under hypothermic circulatory arrest. In the other 5, SG was deployed without any type of endoleak. Postoperative complication included incomplete phrenic nerve palsy in 1. Prophylactic bypass for LCCA was divided because SG did not obstruct the antegrade flow of LCCA. Revascularization of neck vessels can be performed with low morbidity in endovascular repair of aortic arch aneurysms.

Aged↗

PubMed2005

Pathologies of the uterine endometrial cavity: usual and unusual manifestations and pitfalls on magnetic resonance imaging.

The endometrial cavity may demonstrate various imaging manifestations such as normal, reactive, inflammatory, and benign and malignant neoplasms. We evaluated usual and unusual magnetic resonance imaging (MRI) findings of the uterine endometrial cavity, and described the diagnostic clues to differential diagnoses. Surgically proven pathologies of the uterine endometrial cavity were evaluated retrospectively with pathologic correlation. The pathologies included benign endometrial neoplasms such as endometrial hyperplasia and polyp, malignant endometrial neoplasms such as endometrial carcinoma and carcinosarcoma, endometrial-myometrial neoplasm such as endometrial stromal sarcoma, pregnancy-related lesions in the endometrial cavity such as gestational trophoblastic diseases (hydatidiform mole, invasive mole and choriocarcinoma) and placental polyp, myometrial lesions simulating endometrial lesions such as submucosal leiomyoma and some adenomyosis, endometrial neoplasms simulating myometrial lesions such as adenomyomatous polyp and endometrial lesions arising in the hemicavity of a septate/bicornate uterus, and fluid collections in the uterine cavity (hydro/hemato/pyometra). It is important to recognize various imaging findings in these diseases, in order to make a correct preoperative diagnosis.

Adult↗

PubMed2005

Abdominal compartment syndrome causing respiratory failure during surgery for a ruptured descending thoracic aneurysm: report of a case.

Elevated intra-abdominal pressure causing widespread organ dysfunction is known as abdominal compartment syndrome (ACS). The subject of our case report is a 64-year-old man who underwent repair of a ruptured descending thoracic aortic aneurysm (TAA) under deep hypothermic circulatory arrest. During the operation, decompression laparotomy was required to relieve intra-abdominal hypertension causing respiratory failure, before the patient could be weaned off cardiopulmonary bypass. We report this case to alert surgeons to the fact that ACS can occur during surgery on the thoracic aorta, especially if massive fluid resuscitation is required and venous drainage for extracorporeal circulation is less than optimal. Early recognition and prompt decompression by laparotomy is essential to save the life of the patient.

Abdomen↗

PubMed2005

Reoperations after failure of stent grafting for type B aortic dissection: report of two cases.

We describe our successful management of two patients who suffered complications after stent grafting for Type B aortic dissections. One patient was found to have stent-graft migration, which we treated with repeat aortic stent grafting, and the other patient had a proximal endoleak and total occlusion of the stent graft, which we treated with open surgical repair. We discuss the measures used to assist us in deciding on the most appropriate surgery, as well as the treatment alternatives.

Aged↗

PubMed2005

Use of a soft reservoir bag in a fully heparin-coated closed-loop cardiopulmonary bypass system for distal aortic perfusion during aortic surgery.

A fully heparin-coated closed-loop cardiopulmonary bypass system has recently been introduced into clinical practice. Without a venous reservoir, however, it does not allow control of the preload to the heart. We connected a soft reservoir bag in parallel with a centrifugal pump to enable preload control and clinically evaluated this modified system for distal aortic perfusion during aortic surgery. We have used the modified system in 17 patients since November 2002. For venous drainage, we use long narrow cannulae (21 +/- 2 French). We administered 1 mg/kg heparin without cardiotomy suction and 2 mg/kg heparin with suction. We compared the clinical results with those in 13 patients who underwent distal aortic perfusion with an open cardiopulmonary bypass circuit between January 2002 and February 2004. We also analyzed factors affecting the coagulation system in these 30 patients using multiple regression analysis. With the modified system, venous drainage was adequate despite the use of smaller cannulae, and heparin reduction was not associated with thrombotic complication or elevated D-D dimer levels. Abrupt rises in proximal aortic pressure on aortic cross-clamping could be avoided by allowing blood to drain into the soft reservoir bag. Clinical results were not different from those with an open system. In the multiple regression analysis, the peak activated clotting time tended to correlate with postoperative platelet counts. This system is effective in controlling the preload to the heart and allows the safe reduction of heparin dosage. It therefore seems useful for distal aortic perfusion during aortic surgery.

Aged↗

PubMed2005

Risk of spinal cord injury after operations of recurrent aneurysms of the descending aorta.

BACKGROUND: Degenerative disease of the aorta usually involves the occlusion of several intercostal and lumbar branches by mural thrombus or atherosclerotic plaques, suggesting that the blood supply to the spinal cord is mainly provided through collateral networks. Patients with previous abdominal aortic aneurysm repair and subsequent thoracoabdominal aortic reconstruction must undergo ligation of a number of these segmental arteries, presenting a greater risk of experiencing spinal cord ischemic injury. METHODS: The records of 18 patients who had experienced abdominal aortic aneurysm graft replacement and who had undergone 19 operations for thoracoabdominal aortic repair were retrospectively evaluated. All patients were male. The mean age was 66 +/- 10 years (range, 36 to 75 years); the mean interval between the two operations was 79 +/- 69 months (range, 1 to 231 months). There were 18 (95%) cases of thoracoabdominal aortic aneurysms, and one (5%) case of acute dissection of the thoracoabdominal aorta. The origin of the Adamkiewicz artery was determined preoperatively by computed tomography. Measures to avoid spinal cord injury included monitoring of evoked spinal cord potentials and selective reconstruction of the intercostal arteries under hypothermic cardiopulmonary bypass. RESULTS: There were three (16%) cases of permanent neurologic injury that included one cerebrovascular accident, one neurogenic bladder, and one paraparesis of the right lower limb. There were no cases of paraplegia or postoperative deaths. CONCLUSIONS: Surgical reconstruction of the thoracoabdominal aorta in patients who previously underwent abdominal aortic graft replacement is not related to an increased probability of developing spinal cord ischemic injury.

Adult↗

PubMed2005

Evolving strategy and results of spinal cord protection in type I and II thoracoabdominal aortic aneurysm repair.

PURPOSE: We report our strategy and results of spinal cord protection in Crawford I and II thoracoabdominal aortic replacement. : METHODS: Retrospective analysis of 43 elective operations. Before 1994, we reconstructed segmental arteries during a single period of blood flow interruption in 11 of 12 patients, using distal aortic perfusion and evoked spinal cord potential (ESCP) monitoring. Deep hypothermia was used in one. Since 1994, we used multi-segmental sequential repair, in which T8-L1 arteries were sequentially reconstructed irrespective of evoked potential change, in 20 of 31 patients. In the remaining 11, deep hypothermia was used. Cerebrospinal fluid drainage (CSFD) was introduced in 1996 (n=26), and continuous infusion of naloxone in 1999 (n=17). RESULTS: In patients undergoing distal aortic perfusion without multi-segmental sequential repair, six spinal cord injuries including two deaths occurred. Change in evoked potentials was observed in nine of 10 monitored patients. With multi-segmental sequential repair, only one spinal cord injury occurred, and three of 11 monitored patients showed evoked potential change. With deep hypothermia, no spinal cord injury occurred. Multivariate analysis identified operation without multi-segmental sequential repair as a risk factor for spinal cord injury (p=0.008). CONCLUSION: Evolving strategy resulted in an improved outcome. Both multi-segmental sequential repair and deep hypothermia were more effective than our previous technique.

Adult↗

PubMed2005

Cerebral hyperperfusion in a patient with eclampsia with perfusion-weighted magnetic resonance imaging.

The patient was a 25-year-old Japanese woman with postpartum eclampsia, in whom magnetic resonance imaging (MRI) was performed ten hours after convulsion. The patient improved within three days. Diffusion-weighted images showed a high apparent diffusion coefficient (ADC), and perfusion-weighted images obtained by the multi-slice flow-sensitive alternating inversion recovery (FAIR) method showed hyperperfusion, which was suggestive of vasogenic edema, on the parietal and occipital subcortical white matter, corresponding with transient hyperintensities on T2-weighted images. MR angiography (MRA) revealed no signs of vasospasm. These findings suggested hyperperfusion-induced vasogenic edema without cerebrovascular spastic change in the early stage of eclampsia. The FAIR method is considered a useful technique for perfusion-weighted MRI, especially useful to evaluate the cerebral perfusion of emergency patients such as those with eclampsia.

Adult↗

PubMed2005

A case of adenomyomatous polyp of the uterus associated with tamoxifen therapy.

A case of adenomyomatous polyp of the uterine endometrium is reported. The patient was 64-year-old woman treated with tamoxifen. Ultrasonography demonstrated a heterogeneous hyperechoic mass with small cystic spaces in the uterus. On magnetic resonance imaging (MRI), a thick stalk with many thin restiform branches within a large solid and cystic endometrial mass showed dendriform low intensity on T2-weighted images and intense enhancement on contrast-enhanced T1-weighted images. The prominent dendriform central fibrous core on MRI reflected a thick stalk originating from the myometrium with numerous branches containing abundant smooth muscle fibers, and may represent the pathologic feature of adenomyomatous polyp.

Adenomatous Polyps↗

PubMed2004

Tau protein in the cerebrospinal fluid is a marker of brain injury after aortic surgery.

BACKGROUND: Tau is a protein localized primarily in neurons, especially in the axonal compartment. Cerebrospinal fluid tau levels are elevated in acute stroke and head traumas. The purpose of this study is to elucidate the alterations of cerebrospinal fluid tau levels in patients with or without neurologic complication after aortic surgery. METHODS: Twenty-eight patients undergoing descending thoracic (n = 8) or thoracoabdominal (n = 20) aortic surgery were enrolled. Cerebrospinal fluid tau levels were measured before operation and at seven time points up to the 72nd postoperative hour, and were compared with cerebrospinal fluid S100B levels. RESULTS: Two patients developed brain infarction, including the one with paraplegia. In these patients, 20-fold to 100-fold tau elevation was observed, but S100B elevation was less evident in the patient without paraplegia. Three other patients developed spinal cord injury. Additional three patients suffered from temporary neurologic dysfunction of the brain. Tau levels in the latter three patients showed tenfold elevation and were higher than those in the three patients with spinal cord injury or those in the patients without neurologic complication up to 24 postoperative hours. The S100B levels were also higher in the three patients with temporary neurologic dysfunction of the brain than in the patients without neurologic complication at the conclusion of surgery. From 6 to 24 postoperative hours, they were higher in the three patients with spinal cord injury than in the patients without neurologic complication. CONCLUSIONS: These preliminary results suggest that cerebrospinal fluid tau levels reflect brain injury. Because tau levels may separate the patients with temporary neurologic dysfunction, they may serve as a useful marker of brain injury.

Adult↗

PubMed2004

Naloxone lowers cerebrospinal fluid levels of excitatory amino acids after thoracoabdominal aortic surgery.

OBJECTIVE: Although naloxone has been used to prevent ischemic spinal cord injury (SCI), its effect on excitatory amino acids (EAAs) has not been understood. We investigated the clinical significance of naloxone by measuring EAAs in the cerebrospinal fluid (CSF) in patients undergoing thoracoabdominal aortic surgery. METHODS AND SUBJECTS: Twenty-seven patients (15 men and 12 women; mean age, 66 +/- 12 years) undergoing prosthetic replacement of the thoracoabdominal aorta (n = 19) or the descending thoracic aorta (n = 8) from April 1997 to June 2003 under distal perfusion and mild hypothermia were enrolled in this cohort study with historical controls. Their etiology was 7 dissections and 20 nondissections. In 16 patients (naloxone group), intravenous infusion of naloxone (1 microg/kg/h) was continued until the patients became alert. In the remaining 11 patients (control group) naloxone was not given. CSF drainage was used in all patients. CSF levels of EAAs, glutamate, aspartate, and glycine were measured at 6 points in time until 72 hours postoperatively, using a high-performance liquid chromatography method. RESULTS: In 5 patients with SCI (2 patients in control group, 3 in naloxone group), CSF levels of glutamate and glycine continued to increase even at 72 hours postoperatively, and were significantly more elevated than those in patients without SCI ( P < .0001, glutamate; P = .0006, glycine). Postoperative maximum levels of CSF glutamate and glycine were also significantly higher in patients with postoperative SCI than in patients without SCI (glutamate: 215.3% +/- 158.6% vs 32.9% +/- 37.3% increase from baseline, P < .0001; glycine: 309.1% +/- 218.2% vs 89.2% +/- 103.1% increase from baseline, P = .0036). CSF levels of glutamate and aspartate in naloxone group were significantly lower than those in control group ( P = .0161, glutamate; P < .0001, aspartate). Postoperative maximum level of CSF aspartate was also significantly lower in the naloxone group than in the control group (8.3% +/- 75.5% vs 119.7% +/- 120.6% increase from baseline, P = .0077). In multivariate logistic regression analysis, postoperative maximum CSF glutamate >100% from baseline ( P < .001) and postoperative maximum level of CSF glycine ( P = .005)were identified as the independent risk factors for SCI. Both SCI ( P < .001) and postoperative maximum level of CSF glycine ( P = .005) were the independent predictors for postoperative maximum level of CSF glutamate >100% from baseline. CONCLUSIONS: CSF levels of EAAs are elevated in patients with SCI. CSF glutamate is the strongest independent predictor of SCI. Naloxone is effective in lowering CSF levels of EAAs.

Adult↗

PubMed2004

Difference of signal change by a language task on autistic patients using functional MRI.

OBJECTIVE: Cerebral function with a language task was evaluated by functional magnetic resonance imaging (MRI), and the differences of activated pattern and signal changes were compared between autistic patients and normal controls. METHODS: Ten autistic and ten normal subjects were tested by fMRI with a language task requiring the attribution of complex mental states. Activation maps analyzed between two groups were generated and the asymmetry indexes calculated by the quotient of activated pixels of the right frontal lobe divided by those of the left frontal lobe were statistically compared by unpaired t-test. RESULTS: Both the autistic and the normal subjects showed activation at the bilateral prefrontal cortical areas and the ventral occipito-temporal regions. However, the autistic patients demonstrated more activation at the right frontal lobe than the normal controls. Thus it was considered that in the autistic patients the right-hemisphere was more dominant for the language task than that of the normal controls. The result is consist to the theory that autism is related to early left-hemisphere dysfunction. CONCLUSIONS: We considered that fMRI may be a useful non-invasive method to evaluate the cerebral functional abnormality in autistic patients.

Adolescent↗

PubMed2003

Surgical management of aneurysms of the aortic arch vessels and their branches: report of four cases.

We review the cases of four patients with aneurysms of the aortic arch vessels and their branches. Two patients had a subclavian artery aneurysm, one had an innominate artery aneurysm, and one had a carotid artery aneurysm. We performed surgical reconstruction in all four patients in view of the life-threatening complications of these aneurysms. The approach, methods of surgical repair, and cerebral protection are discussed following these four case reports.

Aged↗