Takashi Narisawa

Clinical study of biocompatibility between open and closed heparin-coated cardiopulmonary bypass circuits.

The objective of this study was to investigate the difference between the closed circuit system and the open circuit system in clinical heparin-coated cardiopulmonary bypass (CPB) circuits with a centrifugal pump. We evaluated the coagulation, fibrinolysis, and inflammatory response in valvular heart surgery. Nineteen patients were assigned at random to a group for the closed circuit system or the open circuit system. This is the first report on the effect of a closed circuit in valvular surgery. We measured the platelet count, white blood cell count, plasma fibrinogen concentration, thrombin–antithrombin III complex, plasmin-Α2 plasmin inhibitor complex, D-dimer, interleukin-6, polymorphic neutrophil-elastase, and the plasma free hemoglobin. Blood samples were collected before the start of perfusion, 15 and 60 min after the start of perfusion, 60 min after the administration of protamine, and 1 day after the operation. During the perfusion, coagulation, fibrinolysis, and inflammatory responses were activated; however, no significant differences between the two groups were noted. In this clinical investigation with suction and the cell saving system, the closed circuit was not found to be superior to the open circuit with regard to biocompatibility.

The retroperitoneal approach to aortoiliac surgery associated with a horseshoe kidney: report of a case.

The presence of a horseshoe kidney associated with aortoiliac vascular disease poses technical difficulties in terms of vascular reconstruction. The renal isthmus, position of the renal pelvis and ureters, and variable blood supply to the horseshoe kidney can complicate aortoiliac reconstruction. The left retroperitoneal approach provides excellent exposure of the abdominal aorta in patients with a horseshoe kidney without dividing the renal isthmus and avoids the risk of injury to a ureter in an anomalous position. We herein report the case of a patient with a horseshoe kidney who underwent a successful reconstruction of aortoiliac vascular disease using the left retroperitoneal approach.

Coronary artery bypass grafting in dialysis patients.

OBJECTIVE In dialysis patients, there are two issues to consider, water-electrolyte control and a bypass technique for a calcified aorta. We used continuous hemofiltration for water-electrolyte control and an off-pump bypass with arterial grafting for a calcified aorta. METHODS We performed coronary artery bypass grafting with extracorporeal circulation in 9 cases and without extracorporeal circulation (off-pump bypass) in 3 cases. In 6 cases, the operation was urgent, and in 6 cases the operation was elective. RESULTS An average of 3.2 grafts/pt, (the arterial graft: 1.3 grafts/pt) was performed in the pump cases. In the off-pump bypass cases we used arterial grafting only (1.7 grafts/pt). We had 1 early death (sudden death) and 1 hospital death (SLE encephalopathy). One late death due to cerebral bleeding occurred at 2 years later. We used continuous hemofiltration for 2 to 11 days (average 3.9 days) in the pump cases. The off-pump cases could be controlled by conventional hemodialysis. CONCLUSION Continuous hemofiltration was very easily set up with less interference to the hemodynamics. Using an arterial graft with off-pump bypass, an aortic no-touch technique and water control with conventional hemodialysis were possible.

Technical considerations using a composite graft for aortic root replacement.

We performed modified aortic root replacement using a composite graft in seven patients over a 7-year-period. Six patients underwent emergency surgery for acute aortic dissection and one patient underwent elective surgery for an aortic aneurysm. To make the composite graft, we chose an artificial valve that was 1 mm larger than the graft, and when performing the proximal anastomosis, we sutured only the graft edge using the horizontal mattress suture technique, applying an additional running suture for reinforcement. The button technique was routinely used for coronary reattachment. To assess hemostasis of the aortic proximal and coronary suture line, cardioplegia was injected via the left atrial vent, which enabled us to confirm hemostasis before performing the distal anastomosis. Blood loss and the need for blood transfusion were minimized by this modified technique. None of the six survivors has required reoperation during 7-year period. Our technique of aortic root replacement based on a composite graft with some operative modifications seems to be safe and reliable, resulting in a satisfactory outcome.

A Pseudoaneurysm after Repair of Thoraco-Abdominal Aortic Aneurysm

We report a 63-year-old female patient developing a pseudoaneurysm three years after patch-plasty of an aneurysm located at the distal thoracic aorta. Redo-operation was performed including total replacement of the descending thoracic aorta with reimplantation of distal intercostal arteries using small-caliber interposition grafts. This case presentation underlines the ineffectiveness of patch repair for the treatment of aortic aneurysms. Furthermore, the surgical technique of reimplantation of intercostal arteries using a separate graft is discussed.

Mitral regurgitation after myocardial infarction. Coronary artery bypass grafting and mitral valve replacement with chordae preservation.

A patient with acute ischemic mitral regurgitation after acute myocardial infarction required emergency coronary artery bypass grafting and mitral valve replacement with chordae preservation. For severe mitral regurgitation and heart failure due to myocardial infarction and ischemic papillary muscle dysfunction, mitral valve replacement with chordae preservation was effective. Here, we discuss the etiology of ischemic mitral regurgitation and the operative method for valve repair or replacement.

Preliminary examination to determine the suitable contrast material injection protocol for CT angiography of the pelvis and lower extremities with a multidetector row helical scanner

PurposeThe aim of this study was to determine the best of three protocols for the depiction of arteries in the pelvis and lower extremities by computed tomographic angiography (CTA) with a multidetector row helical scanner.Materials and methodsCTA was performed in five asymptomatic volunteers using a four-channel multidetector row helical scanner. Low-osmolar iodinated contrast material was injected at the flow rate of 3 ml/s using three protocols: 100 ml of 300 mg I/ml, 150 ml of 300 mg I/ml, and 100 ml of 350 mg I/ml. The CT number of opacified blood was measured at six levels. Three doctors independently assessed the degree of depiction of arteries on CTA images without knowing the protocol using a 3-point scale.ResultsCT numbers at the level of the popliteal artery on the protocol of 150 ml of 300 mg I/ml were significantly greater than the others. The mean score for the depiction of trifurcation on the protocol of 150 ml of 300 mg I/ml was significantly greater than those in the others.ConclusionThe protocol of 150 ml of 300 mg I/ml was the best for depicting arteries in the pelvis and lower extremities by CTA.

Evaluation of highly damaged renal function following extracorporeal circulation —Usefulness of alpha 1-microglobulin index—

The patients with highly damaged renal functions following extracorporeal circulation (ECC) were reviewed. Markers such as serum and urine creatinine (SCr, UCr), blood urea nitrogen (BUN), alpha 1-microglobulin in urine (as a marker of renal tubular function, abbreviated as U alpha 1-m), microalbumin in urine (as a marker of renal glomerular function, abbreviated as UA1b) were measured in each cases. Twenty patients were selected with the maximum value of U alpha 1-mover 60 micrograms/dl during or after ECC. The patients were classified into three groups according to preoperative value of alpha 1-m index (alpha 1-m index (I) = U alpha 1-m/UCr x 100 mg/g Cr), and Albumin index (Albumin index (I) = UA1b/UCr x 100 mg/g Cr). Group I (n = 13); alpha 1-m I > 10 and, Alb I > or = 50 (abnormal value of tubular and glomerular function), Group II (n = 3); alpha 1-m I < or = 10, Alb I > or = 50 (abnormal value of glomerular function), Group III (n = 4); alpha 1-m I < or = 10, Alb I < 50 (normal value of tubular and glomerular function). Six patients in Group I required postoperative hemodialysis (HD) and one patient in Group II. No one required HD in Group III. These facts suggest that preoperative damage of tubular and glomerular functions may become prolonged or irreversible damages may occur after operation. HD is required frequently in patients with alpha 1-m I level over 500 mg/g Cr, especially continuous HD may be needed in patient with alpha 1-m I level over 1000 mg/g Cr.