Satoru Kuki

Mycotic aneurysm of the infrarenal abdominal aorta infected by Clostridium septicum: A case report of surgical management and review of the literature

We report a surgical case of mycotic aneurysm of the infrarenal abdominal aorta infected by Clostridium septicum. The patient was first treated with an in situ prosthetic graft replacement. When the infection recurred 5 weeks after the aortic surgery, the patient was successfully treated by transposition of rectus abdominis muscle flap around the graft. Only 19 cases of mycotic aneurysm or aortic dissection caused by Clostridium septicum have been reported. Ten of 12 patients who underwent vascular surgery survived, whereas all 7 patients who did not undergo surgery died. Surgical treatment should be undertaken since the surgical results seem satisfactory.

Evaluation of the Mitral Valve Leaflet Morphology after Mitral Valve Reconstruction with a Concept “Coaptation Length Index”

Abstract  Background: In clinical settings, information on morphology of mitral valve leaflet after mitral valve reconstruction is limited. Methods: Between January 1996 and June 2000, 36 underwent mitral valve repair for mitral regurgitation (MR). The etiology of mitral insufficiency was prolapse, dilated annulus, and ischemic. Ring annuloplasty was performed in all cases. Mitral valve short‐axis dimension (MVd), vertical distance between annular line and closing point (Vd), coaptation length (CL), coaptation length index (CL/MVd) were measured by the two‐dimensional transesophageal echocardiography for the present 11 cases. Results: In 11 cases, residual MR, using a scale from 0 to 4, was 0 in 5 patients, 1 in 4 patients, 2 in 2 patients whose etiology of regurgitation was cardiomyopathy. MVd and Vd decreased significantly (38.7 ± 6.2 to 27.0 ± 5.6 mm, 10.1 ± 7.7 to 6.5 ± 4.6 mm, respectively). CL and CLI increased significantly (6.4 ± 2.4 to 11.6 ± 4.6 mm, 0.16 ± 0.06 to 0.44 ± 0.21, respectively). Among those index, only CLI have a statistically significant negative correlation with the degree of residual MR. Conclusion: The mitral valve ring annuloplasty produce the morphologic change of mitral apparatus, especially the increase of CLI, which may be one of the main factors in regulation of regurgitation.

Arch Aneurysm Repair With Long Elephant Trunk: A 10-Year Experience in 111 Patients

BACKGROUND We studied the long-term outcome of arch aneurysm repair with a long elephant trunk (LET) anastomosed at the base of brachiocephalic artery. METHODS Between 1998 and 2008, 111 patients underwent arch aneurysm repair with LET. A 4-branched graft was sutured to the sinotubular junction, the distal ascending aorta transected, and a LET inserted into the aortic arch while selective cerebral perfusion was maintained. The graft distal end was anastomosed to the LET, incorporating the distal ascending aorta, and arch vessels were anastomosed to graft branches. RESULTS Concomitantly, 33 patients (30%) underwent other cardiac procedures, including 11 aortic root replacements. Two patients died (1.8%) within 30 days and 7 died (6.3%) after 30 days. Perioperative morbidity included 2 (1.8%) with stroke, 3 (2.7%) with paraplegia, and 1 (0.9%) with paraparesis. Postoperative computed tomography scans revealed complete aneurysmal thrombosis around the LET in 88 patients (79%), who were monitored without a second-stage procedure. Among 23 patients with incomplete thrombosis, 19 underwent a second-stage procedure to complete distal fixation of the LET. Overall survival was 88%, 83%, and 75%, at 1, 3, and 5 years after aneurysm repair with the LET. No aneurysm rupture or reexpansion occurred in patients with complete thrombosis. Four patients with incomplete thrombosis died of rupture before the second-stage procedure. CONCLUSIONS Our results demonstrated safety and good durability of the LET technique and suggest that this technique is a simple and safe procedure that is applicable to a variety of arch aneurysms.

Successful surgical management for multiple cerebral mycotic aneurysms involving both carotid and vertebrobasilar systems in active infective endocarditis.

Mycotic aneurysm is usually found in the middle cerebral artery associated with infective endocarditis. Previous reports we have identified include only 4 cases of vertebrobasilar aneurysm. We report on a 29-year-old female who had multiple mycotic aneurysms involving both the carotid and vertebrobasilar systems complicated by intracranial hemorrhage with infective endocarditis, in whom staged operations, mitral valve replacement and craniotomies, were successfully performed.

Usefulness of continuous air tonometry for evaluation of splanchnic perfusion during cardiopulmonary bypass.

Although gastric mucosal tonometry has been reported as a useful method to assess splanchnic perfusion during cardiovascular surgery, the conventional discontinuous method of tonometry (saline tonometry) was cumbersome and prone to systematic errors. A new automated system of air tonometry (Tonocap; Datex Ohmeda, Helsinki, Finland) allows for frequent (every 10 minutes) measurement of gastric regional CO2 (PrCO2) and may be more suitable as a monitoring system in cardiac patients. We evaluated the usefulness of continuous air tonometry as a marker of splanchnic perfusion during cardiopulmonary bypass (CPB). In 19 patients (53–79 years, mean 63 years) who underwent cardiovascular surgery under standard CPB with mild hypothermia (32°C) from January 2001 to May 2002, the PrCO2 and calculated intramucosal pH (pHi) of gastric tonometry was monitored using Tonocap, and their relation to postoperative visceral organ function was evaluated. The pHi significantly increased after initiation of CPB from 7.32 ± 0.07 to 7.43 ± 0.10 (p < 0.05) and then consistently decreased in all patients to 7.39 ± 0.09 at the end of CPB. The value of PrCO2 significantly (p < 0.01) correlated with the value of pHi. The lowest value of pHi during CPB was significantly related to blood urea nitrogen (r = −0.75, p < 0.05), serum creatinine (r = −0.78, p < 0.05), creatinine clearance (r = 0.68, p < 0.05) on postoperative day 1, and blood urea nitrogen (r = −0.84, p < 0.01) on day 3. In contrast, arterial blood lactate level, venous oxygen saturation, and routinely measured hemodynamics (e.g., pump flow, arterial pressure) during CPB were unrelated to the postoperative visceral organ function. These results suggest that continuous monitoring of gastric regional CO2 and pHi by air tonometry system is useful for the evaluation of splanchnic perfusion during CPB and may contribute to improve CPB technique by allowing the early detection of visceral malperfusion.

Leakage of cytoplasmic enzymes from rat heart by the stress of cardiac beating after increase in cell membrane fragility by anoxia

The effects of spontaneous beating after anoxia and the pumping stress induced by a left ventricular balloon on the leakage of myocardial enzymes from the isolated perfused rat heart were investigated. Beating of the heart was arrested by perfusion with high-K+ medium. When the beating was arrested during reoxygenation after anoxia, the leakage of lactate dehydrogenase (LDH) was significantly lower than during reoxygenation with spontaneous cardiac beating. After changing from K+ arrest to spontaneous beating by perfusion with low-K+ medium during reoxygenation, the leakage of LDH increased markedly. Imposition of left ventricular wall stress on the K+-arrested heart by repetitive passive distension during aerobic perfusion and after 20 min and 60 min of anoxia caused LDH leakages of 1.0, 4.6 and 21.0 units/g in 30 min, respectively. Under this mechanical stress, the release of LDH as a percentage of its total myocardial activity coincided well with that of cytoplasmic aspartate aminotransferase (AST), while the percentage release of mitochondrial AST was much less. These results appeared to indicate that the leakage of cytoplasmic enzymes during reoxygenation is accelerated by cardiac beating because of fragility of the cell membranes developing during the preceding anoxia.

Total arch replacement with long elephant trunk anastomosed at the base of the innominate artery: a single-centre longitudinal experience.

OBJECTIVE Total arch replacement, with a long elephant trunk (ET) anastomosed at the base of the innominate artery using an undersized graft, is performed for a variety of arch aneurysms. We investigated the long-term clinical outcomes of this procedure, as well as its long-term effectiveness for preventing retrograde flow into the aneurysm and further dilation of the descending aorta. METHODS We treated 127 consecutive patients with an arch aneurysm, who were divided into two groups according to the diameter of the descending aorta at the Th6-Th8 thoracic vertebral level: 35 mm or less (Single-ET, n = 94) and >35 mm (Staged-ET, n = 33). The graft diameter was undersized by 10-20% of the distal aortic diameter. ET length was determined by preoperative computed tomography (CT) to locate the distal end at Th6-Th8. Thrombosis around the ET and the descending aorta diameter around the distal end of the ET were evaluated using CT. RESULTS Two patients (1.6%) died within 30 days, while seven (5.5%) died in the hospital, three (2.4%) had a new stroke, three (2.4%) had permanent paraplegia and one (0.8%) had paraparesis. CT demonstrated complete thrombosis of the perigraft space around the ET in 81 patients (86%) in the Single-ET group and 11 (33%) in the Staged-ET group within 1 month after surgery, but not in the remaining 35 patients. Twenty-seven of the 35 patients without complete thrombosis underwent a subsequent second-stage operation. In those, the descending aorta showed no further dilation around the distal end of the ET, while new-onset perigraft perfusion occurred in two patients in the Single-ET group at 14 and 126 months, respectively. Overall survival was 89, 86, 78 and 74% at 1, 3, 5 and 7 years, respectively. CONCLUSIONS Our operative strategy for extensive thoracic aortic aneurysms using a long ET technique yielded satisfactory short- and long-term outcomes.

Evaluation of prostacyclin analogue OP-41483 as an adjunct to crystalloid cardioplegia in infants and children

A chemically stable prostacyclin analogue (PGI2-A, carbacyclin, OP-41483) was evaluated as an adjunct to potassium cardioplegia in infants (n = 13) and children (n = 32), in whom the current potassium cardioplegia may be limited in its effects. PGI2-A was added in a dose of 300 micrograms/L to the potassium cardioplegic solution. Postoperatively, peak levels of the myocardial-specific isoenzyme of creatine kinase (MB-CK) were compared for the PGI2 group and a control group (n = 65). In patients 1 year of age or older (n = 32 and 49 for the PGI2 and control groups, respectively), the MB-CK level was significantly lower in the PGI2 group only when compared between the subgroups with an aortic cross-clamp time of 120 minutes or more (n = 9 and 10; MB-CK level, 35.2 +/- 15.6 vs 68.3 +/- 32.4 IU/L;p less than 0.05). In patients less than 1 year of age, in whom aortic cross-clamp times were generally less than 120 minutes, the MB-CK level was also lower in the PGI2-A group than in the control group (n = 13 and 16; MB-CK level, 33.6 +/- 14.3 vs 61.6 +/- 36.3 IU/L;p less than 0.05). Infants less than 6 months of age (n = 18) underwent ultrastructural assessment of left ventricular myocardial biopsy specimens, and the PGI2-A group showed better results in mitochondrial and intracellular edema scores. This clinical trial showed beneficial effects of PGI2-A used with crystalloid potassium cardioplegia in infants and children.

Sodium-23 MR imaging of the kidney in guinea pig at 2.1 T, following arterial, venous, and ureteral ligation

In vivo 23Na magnetic resonance images of guinea pig kidney were obtained at 2.1 T using a spin‐echo sequence with an echo time of 19 ms. The intact kidney showed a very strong signal intensity in the sodium image. The signal intensity of the kidney decreased to 55% after ligation of the renal artery together with the vein and the ureter. The total sodium content in the excised kidney after arterial occlusion, measured by flame photometry, was 24% higher than that in the intact kidney. The transverse relaxation time (T2) of the extracellular sodium in the isolated kidney decreased to one‐third of that in the intact kidney. This shortening of T2 may be partly responsible for the decrease in the 23Na signal intensity from the kidney after arterial occlusion.

Usefulness of the low profile True 8 intra-aortic balloon pumping catheter for preventing limb ischemia

The most important limitation in the use of an intra-aortic balloon pumping (IABP) is the risk of vascular complications. Recently, an IABP catheter with an 8.0 French shaft and low profile that may decrease the risk of vascular morbidity has been developed. We evaluated the in vitro balloon performance and the prevention of limb ischemia in clinical use. An 8.0 French IABP catheter was compared with a standard 9.5 French catheter. Inflation time (IT), deflation time (DT), and changes in volume (V) generated by the balloon were measured during the pumping cycle in an experimental model. The inflation velocity (V/IT) and deflation velocity (V/DT) were calculated as parameters of balloon performance. At 120 bpm the V/IT and V/DT were 0.34 ml/msec and 0.28 ml/msec with the 8.0 French, and 0.33 ml/msec and 0.24 ml/msec with the 9.5 French catheter. Twelve patients with coronary artery disease, ranging in age from 41 to 87 years (mean, 66 years), who underwent IABP support, were divided into group 1 (8.0 French, n = 4) and group 2 (9.5 French, n = 8). Ankle-arm pressure index (API), lactate extraction ratio (LER) in the limb with IABP insertion, and cardiac index (CI) were measured at 1, 12, and 24 hours postoperatively. There were no major vascular complications and no counterpulsation related morbidity. There was no significant difference between the two groups with regard to age, duration of IABP support, and incidence of peripheral vascular disease and diabetes. The percentage of women patients was significantly higher in group 1 (100%vs. 25%), whereas body surface area was significantly smaller (1.45 ± 0.14 vs. 1.68 ± 0.12 m2). The API in group 1 were slightly higher than those in group 2 throughout the observed period (not significant). The LER and CI showed no significant differences between the two groups. These results suggest that the 8.0 French IABP catheter with a low profile has an acceptable in vitro performance, and its clinical application may be effective in preventing limb ischemia in a high-risk subset of patients such as women and smaller patients.