Concentrated platelets harvesting before cardiopulmonary bypass improved cardiac and pulmonary function.

BACKGROUND: Sequestration of concentrated platelets (P-con) during cardiopulmonary bypass (CPB) has been performed to preserve platelet function after cardiac surgery. Since P-con also harvests leukocytes simultaneously, there might be a possibility that the inflammatory effects or ischemia-reperfusion injuries associated with CPB, such as a cardiac or pulmonary dysfunction after cardiac surgery, are reduced with its use. METHODS: We retrospectively evaluated 53 patients who underwent cardiac surgery after the introduction of the P-con technique at our institute. There were 20 patients in the P-con group and 33 patients in the control group in whom concentrated platelet were not harvested. RESULTS: The patients characteristics and preoperative cardiac and pulmonary function did not differ between the two groups. The percentages of platelets and leukocytes sequestrated were 20.2+/-5.4% and 8.5+/-3.9% of the total estimated circulating cell counts, respectively. There were no significant differences in the postoperative dose of dopamine used, cardiac index, pulmonary capillary wedge pressure or intubation period between the two groups. However, the stroke volume index (p=0.005), left ventricular stroke work index (p=0.002), and ratio of the arterial oxygen tension to the inspired fraction of oxygen on extubation (p=0.02) were significantly greater in the P-con group as compared with those in the control. CONCLUSIONS: P-con improved cardiac and pulmonary function after CPB. Simultaneous sequestration of platelets and leukocytes by P-con during CPB may contribute to the improvement of cardiac and pulmonary function after cardiac surgery.

[Early and late results of composite graft replacement for the aortic root].

From 1985 to 1998, 16 patients underwent composite graft replacement for the aortic root. Ten patients (63%) had Marfan syndrome, 11 (69%) had annulo aortic ectasia (AAE), and 7 (44%) had Stanford A dissection. Two patients (12.5%) underwent emergent operation due to acute aortic dissection. There were 2 (12.5%) operative deaths, and both were Stanford A dissection without Marfan syndrome. Although there was no statistical significance, the operative mortality was higher for the patients with Stanford A dissection (p = 0.087), for those with emergent operation (p = 0.074) and for those without Marfan syndrome (p = 0.051). The overall survival rates were 87.5% at 5 years and 75% at 10 years. The survival rate at 8 years was significantly lower for the patients with Stanford A dissection (35.7%) as compared with non-Stanford A dissection (100%, p = 0.024). Neither Marfan syndrome nor AAE affected the long-term survival. The late results of composite graft replacement for the aortic root were satisfactory except for the patients with Stanford A dissection. It was suggested that the long-term survival for Stanford A dissection was greately affected by the operative deaths for Stanford A dissection without Marfan syndrome.

Pretreatment of a Dacron graft with tissue factor pathway inhibitor decreases thrombogenicity and neointimal thickness: a preliminary animal study.

The purpose of this study was to evaluate the effects of locally applied TFPI on the reduction of neointimal thickness in Dacron grafts. Seven millimeter internal diameter 5 cm lengths of albumin coated knitted Dacron grafts were interposed in the infrarenal aorta in 14 mongrel dogs. Before implantation, the grafts were immersed in saline solution containing 200 microg/ml of TFPI (TFPI group, n = 7) or 100 IU/ml of heparin (control group, n = 7) for 15 minutes at room temperature. Three months after implantation, neointimal thickness and percentage of graft stenosis were measured by computerized planimetry. All grafts were patent 3 months after implantation. Thrombus was found in one graft in the TFPI group, but observed in three of seven control grafts. Neointimal thickness in the TFPI group was significantly smaller than that in the control group (mean +/- SD, 0.26 +/- 0.1 mm vs. 0.57 +/- 0.15 mm, p < 0.001). Percentage of graft stenosis was significantly lower in the TFPI group than in the control group (13.4 +/- 5.3% vs. 26.9 +/- 7.0%, p < 0.001). Scanning electron micrographs showed that the neointima of TFPI treated grafts were completely covered by endothelial cells. The present results indicate that locally applied TFPI reduces thrombogenicity and neointimal thickness in albumin coated knitted Dacron grafts.

Functional, metabolic, and histological changes of vascular tissues after warm ischemia.

We examined functional, metabolic, and histological changes in the aortic tissue of rats after the period of warm ischemia ranging from 0 to 24 hours to determine the window of time in which grafts can be optimally viable for harvest. Sixty aortas from Brown Norway rats obtained after warm ischemia were used and changes in contraction, endothelial-dependent or -independent vasodilatation, cell viability, and histology were examined. Maximal contraction induced by norepinephrine and potassium chloride decreased time-dependently after exposure to warm ischemia. The warm ischemic period when 50% of the maximal contractile response of freshly isolated arteries was preserved, ranged from 6 to 8 hours. Maximal endothelium-dependent relaxation induced by acetylcholine decreased along with the time of warm ischemia. Endothelium-independent relaxation induced by sodium nitroprusside and forskolin was unaltered for up to 9 hours. Cell viability gradually decreased, and a significant negative correlation was found between warm ischemic period (T: hours) and cell viability (V: %) (V=101.9-2.35T; r(2)=0.96; p<0.0001). Cell viability was greater than 70% within 12 hours postmortem. Histologically, after 9-hour-warm ischemia irreversible changes were detected. Results suggest that the period of warm ischemia for up to 6 hours would be acceptable for preservation of tissue viability.

Topically applied tissue factor pathway inhibitor reduced intimal thickness of small arterial autografts in rabbits.

PURPOSE: The purpose of this study was to investigate whether topically applied tissue factor pathway inhibitor (TFPI) reduces intimal thickness and increases long-term patency of small arterial autografts in rabbits. METHODS: An entire 10-mm long section of the left femoral artery was harvested and immersed in saline solution (control group, n = 10), 100 IU/mL of heparin (heparin group, n = 15), or 40 microg/mL of TFPI (TFPI group, n = 15) for 15 minutes. Then the graft was interposed to the right femoral artery. Patency rates were determined by flow measurements throughout the time course of the study, and the grafts were analyzed for measurement of intimal thickness at 3 months after operation. Immunohistochemical analysis was performed to examine whether topically applied TFPI binds to endothelial cells of the grafts. RESULTS: Three-month postoperative patency rates were 10% in the control group, 47% in the heparin group, and 73% in the TFPI group. The TFPI group had a significantly higher patency rate than that of the control group (P <.005). Compared with the heparin group, the TFPI group had a significant reduction in intimal area (0.19 +/- 0.05 mm(2) vs 0.30 +/- 0.09 mm(2), P =.0051), in percentage of stenosis (35.7% +/- 7.7% vs 61.4% +/- 15.8%, P <.0001), and in intimal/media areas ratio (0.64 +/- 0.24 vs. 1.04 +/- 0.33, P =.0051). Immunohistologic analyses confirmed that topically applied TFPI bound to endothelial cells. CONCLUSION: These results indicate that topically applied TFPI reduces intimal thickness and increases long-term patency of small arterial autografts in rabbits.

Antigenicity of cryopreserved arterial allografts: comparison with fresh and glutaraldehyde treated grafts.

The use of cryopreserved aortic allografts in cardiovascular surgery is widespread and has resulted in excellent outcomes. However, it is controversial whether cryopreservation suppresses the antigenicity of tissue. We designed experimental models to study whether the cryopreservation process alters antigenicity in comparison with that found in fresh and glutaraldehyde treated tissues. Fresh, cryopreserved, and glutaraldehyde treated thoracic aorta from Brown Norway rats were subcutaneously implanted into Lewis rats. Inflammatory cells infiltrating around the grafts were measured on days 7, 14, 28, and 56 after implantation. The glutaraldehyde treated grafts showed significantly less infiltration than the fresh or cryopreserved grafts (p < 0.005). No significant difference was detected between the fresh and cryopreserved grafts. Another study examined the effect of modifications of the aortic allograft on subsequent allogeneic skin graft antigenicity. Subcutaneous implantation of fresh, cryopreserved, and glutaraldehyde treated aortic grafts from Brown Norway into Lewis rats resulted in subsequent skin graft rejection at 4.4+/-0.7, 5.1+/-0.8, and 6.6+/-2.1 days, respectively. There was no significant difference between the fresh and cryopreserved groups; whereas skin grafts in the glutaraldehyde group survived longer than those in the cryopreserved group. These results indicate that cryopreservation had no significant influence on antigenic suppression of arterial allografts.

Patch reconstruction of the mitral annulus for active infective endocarditis with annular abscess.

Active infective endocarditis is associated with high operative mortality and morbidity. The outcome may be improved by operating at the optimal time using the most appropriate surgical procedure. We describe a 15-year-old man with active infective endocarditis of the mitral valve associated with an annular abscess. Disseminated intravascular coagulation was associated with progressive decrease in the platelet count. The abscess was debrided, the mitral annulus was patch-reconstructed using bovine pericardium treated with glutaraldehyde, then the mitral valve was replaced. The patient was discharged from intensive care unit 3 days after operation with clinical and blood examination improvement. The patient is being observed carefully by periodic follow-up echocardiography, and there is no evidence of PVD, PVE or calcification of the patch during 14 months of follow-up period. Patch reconstruction of the annulus using bovine pericardium treated with glutaraldehyde reinforced the annulus and prevented local reinfection of the prosthesis in this patient.

Consumption coagulopathy associated with aneurysms of the abdominal aorta and the bilateral femoral arteries. Report of a case.

The authors report a case of a 70-year-old man, with repeating episodes of systemic subdermal hematoma due to consumption coagulopathy associated with abdominal aortic aneurysm and the bilateral femoral arterial aneurysms. Prior to the first operation for abdominal aortic repair, anticoagulation therapy was applied to treat thrombocytopenia and hypofibrinogenemia. Five years following the first surgery, the same treatment was required before resection of the femoral lesions. Consumption coagulopathy is seen in approximately 1-4% population of aortic aneurysms, however, repeated appearance of symptomatic coagulopathy is rarely reported. Anticoagulation therapy was effective to normalize the coagulation and fibrinolytic system and followed by uneventful surgical resection of the aneurysms.

[Evaluation of superior transseptal approach for the removal of left atrial myxoma].

We compared the operative outcomes among 14 patients who underwent the removal of left atrial myxoma with four different approaches; right lateral (n = 2), transseptal bi-atrial (Dubost, n = 4), conventional transseptal (n = 4) and superior transseptal approach (STA, n = 4). Concomitant operations were performed in 4 cases (CABG, two; aortic valvuloplasty, one; mitral valve replacement, one), and two out of 4 cases were in the STA group. The mean operation, cardiopulmonary bypass and aortic cross-clamp times were shorter in the STA group compared to the other three group. The total amount of postoperative drain discharge and the peak value of creatine kinase were also lower in the STA group compared to the other three groups. Among the patients in sinus rhythm before operation, the use of STA was associated with a greater incidence (100%) of postoperative atrial fibrillation or junctional rhythm. These rhythm disturbances were temporary, and all returned to sinus rhythms during hospital stay. We conclude that STA is an excellent approach with a nice surgical view to expose and remove the left atrial myxoma.

Resuscitation and evaluation of non-beating hearts obtained from asphyxiated dogs via autoperfusing heart-lung circuit.

BACKGROUND: The shortage of donor hearts has made use of non-beating hearts as cardiac grafts an attractive possibility for heart transplant candidates. The purpose of this study was to evaluate the utility of leukocyte-depleted hot shot cardioplegia for resuscitation of non-beating hearts obtained from asphyxiated dogs via an autoperfusing heart-lung circuit. METHODS: Mongrel dogs were divided into 3 groups according to the warm ischemia time and the method of reperfusion before starting the autoperfusing heart-lung circuit. Group A (n=4) had 60 minutes of warm ischemia and reperfusion without leukocyte-depleted hot shot, Group B (n=5) had 30 minutes of warm ischemia and reperfusion with leukocyte-depleted hot shot, and Group C (n=7) had 60 minutes of warm ischemia and reperfusion with leukocyte-depleted hot shot. We calculated stroke work via the heart-lung circuit to evaluate cardiac function of the resuscitated hearts. The criteria for "recovery" has been reported elsewhere. Myocardial water content of the resuscitated hearts was also measured and analyzed. No inotropic agents were used. RESULTS: The recovery rates in groups A, B and C were 0%, 80% and 57%, respectively, and the group B rate was significantly higher than the group A rate (p=0.04). Although myocardial water content did not differ between groups B and C, it was significantly lower in recovered hearts than in non-recovered hearts (p=0.04). Significant negative correlation was observed between the maximum stroke work value and myocardial water content in the resuscitated hearts (r=0.668, p=0.03). CONCLUSIONS: The autoperfusing heart-lung circuit is useful for evaluation and maintenance of cardiac function. Our experimental data shows that leukocyte-depleted hot shot plays a great role for resuscitation and recovery of non-beating hearts.

[Vascular anastomoses in free jejunal reconstruction to the neck vessels: an experience of consecutive 20 cases without using surgical microscope].

Twenty consecutive cases of pharyngoesophageal cancer who underwent free jejunal reconstruction were reported. The common carotid or external carotid artery was used for a feeder of the free graft. The internal jugular vein were served as a drainage vein. All anastomoses were performed in an end-to-side fashion without using surgical microscopes. Mean carotid artery clamping time was 16 minutes and no neurological complications were noticed postoperatively. Graft failure was occurred in 1 patient. The presenting technique, showing 95% success rate, is recommended as a simple option for vascular anastomosis in free jejunal reconstructive surgery.

[A case of ruptured distal aortic arch aneurysm with bronchiolitis obliterans organizing pneumonia].

We report a case of histologically proved bronchiolitis obliterans organizing pneumonia (BOOP) associated with ruptured distal aortic arch aneurysm (DAAA) into the lung. A 63-years-old male with preoperative episode of hemosputum and hemoptysis was diagnosed DAAA. Preoperative computed tomographic scanning demonstrated that the aneurysm was surrounded with the structure of 2 layers of the enhanced high density external layer and the not enhanced low density internal layer. Combined resection of the left upper lobe and the aneurysm was performed safely because of marked adhesion between the lung and the aneurysm. Postoperative histological examination revealed that the perianeurysmal structure was due to BOOP.

[Hepatic function after surgical repair of constrictive pericarditis].

We report the results of long-term follow up in 9 patients who underwent pericardiectomy for constrictive pericarditis. In order to test whether if congestive liver dysfunction due to the disease could be reversible or not after the surgical repair, the patients were evaluated by indocyanine green (ICG) clearance test. All the patients improved in NYHA classification after long-term periods following surgical repairs. The percentage of ICG retention at 15 minutes (ICG-R15) improved in most of the patients. However, two patients who had a long history from the onset before surgery became worse in ICG-R15. From the above reports, reversibility of hepatic function might be dependent on the duration of liver congestion before surgical repairs.

Activated protein C reduces the ischemia/reperfusion-induced spinal cord injury in rats by inhibiting neutrophil activation.

OBJECTIVE: To examine whether activated protein C (APC) reduces spinal cord injury in rats by inhibiting neutrophil activation after the transient ischemia. SUMMARY BACKGROUND DATA: Ischemic spinal cord injury is an important pathologic mechanism leading to the paraplegia observed after surgery to repair aortic aneurysms. Activated neutrophils play a pivotal role in the development of ischemia/reperfusion-induced tissue injury. Recently, the authors have reported that APC, a physiologic anticoagulant, prevents lipopolysaccharide-induced pulmonary vascular injury by inhibiting neutrophil activation. These observations strongly suggest that APC reduces ischemia/reperfusion-induced spinal cord injury by inhibiting neutrophil activation. METHODS: In rats, spinal cord ischemia was induced by using a balloon catheter placed into the aorta. After the transient ischemia, survival and motor function were evaluated, and histologic examination of the spinal cord was performed by using both hematoxylin-and-eosin staining and 2,3,5, -triphenyltetrazolium chloride (TTC) staining 24 hours after the ischemia. Tissue levels of myeloperoxidase and cytokines, including tumor necrosis factor-alpha (TNF-alpha) and rat interleukin-8, were measured in six experimental groups: sham-operated, control, APC (100 microg/kg, intravenous), dansyl glutamyl-glycyl-arginyl chloromethyl ketone-treated activated factor X (DEGR-F.Xa), a selective inhibitor of thrombin generation (1 mg/kg, intravenous), nitrogen mustard-induced leukocytopenia, and diisopropyl fluorophosphate-treated APC (DIP-APC), active site-blocked APC (100 microg/kg, intravenous). APC, DEGR-F.Xa, and DIP-APC were administered intravenously 30 minutes before aortic occlusion. Control and leukocytopenic rats received saline instead of other drugs. RESULTS: Pretreatment with APC significantly reduced motor disturbances compared with those in control animals. In contrast, neither DEGR-F.Xa nor DIP-APC had any effect. Microinfarctions, evidenced by the absence of TTC staining and histologic change, were markedly reduced in animals given APC. The increases in the tissue levels of TNF-alpha, rat interleukin-8, and myeloperoxidase in the ischemic part of the spinal cord were significantly reduced in animals that received APC. These levels were not reduced in rats given DEGR-F.Xa or DIP-APC. Leukocytopenia produced effects similar to those of APC. CONCLUSIONS: APC reduced the ischemia/reperfusion-induced spinal cord injury by inhibiting neutrophil activation. The therapeutic mechanisms of APC might depend on its inhibitory effect on the production of TNF-alpha, which is a potent activator of neutrophils. Although the anticoagulant effects of APC might not be related to its ability to inhibit TNF-alpha production, its serine protease activity appears to be essential in the therapeutic mechanism. APC appears to have potential as a therapeutic agent for prevention of spinal cord injury in patients undergoing aortic aneurysm repair.

[Indocyanine green (TCG) clearance as a monitor to evaluate right heart function].

Systemic venous return to the heart is disturbed as a result of right heart failure. ICG clearance is known to be influenced by hepatic venous return to the right atrium. Under a hypothesis that right heart function could be evaluated by ICG clearance test, patients with mitral valve disease (Group M, n = 29), aortic valve disease (Group A, n = 16), ischemic heart disease (Group CABG, n = 19) were studied. Preoperative K-ICG (normal range > 0.17) in the Group M was significantly lower than those in the Group A and Group CABG (0.097 +/- 0.037 vs 0.166 +/- 0.032 and 0.171 +/- 0.027, p < 0.05). In the Group M, patients who underwent tricuspid annuloplasty (TAP) had significantly lower K-ICG than the others (0.077 +/- 0.026 vs 0.113 +/- 0.038, p < 0.05). Postoperatively, K-ICG of TAP patients significantly increased (0.092 +/- 0.031, p < 0.05) when compared to their preoperative value. ICG clearance test was useful to quantify the right heart function, especially in the postoperative evaluation.

Thoracoabdominal aortic aneurysm combined with aortic occlusion.

The case of a 73-year-old woman with aneurysms of the thoracoabdominal aorta and distal arch, combined with aortic occlusion, is reported. Cannulation from the femoral artery was not possible because of the aortic occlusion. Blood supply to the abdominal viscera and lower extremities was achieved only by selective perfusion from the celiac artery, superior mesenteric artery, and bilateral renal arteries. A unique choice of selective perfusion for distal circulatory support is described.

Altered plasma antigen levels of tissue factor pathway inhibitor during open-heart surgery.

Tissue factor pathway inhibitor (TFPI) is a potent inhibitor of the extrinsic pathway of the coagulation cascade that is activated by cardiopulmonary bypass (CPB) during open-heart surgery. In the present study, we investigated whether the plasma TFPI antigen increases during CPB in 12 patients who underwent bypass procedures. The plasma levels of free and total TFPI antigens were measured using an enzyme-linked immunosorbent assay, and heparin concentrations were measured using a chromogenic substrate assay. We found that changes in the total plasma TFPI antigen level were significantly dependent on the level of free TFPI antigen (r = 0.96, P < 0.0001) which increased significantly after heparin injection (P < 0.0001), and increased further during the bypass period (P < 0.005). The increased free TFPI antigen level during CPB correlated with the duration of bypass (r = 0.65, P = 0.02). When heparin was neutralized by protamine, the free TFPI antigen level decreased immediately, but remained higher than the preoperative level (P < 0.005). These results suggest that plasma TFPI antigen levels increase during CPB.

A new technique for debridement in rheumatic valvular disease: the rasping procedure.

BACKGROUND: Valve repair is superior to valve replacement in terms of postoperative risk. However, the conventional techniques used for valve repair in patients with rheumatic valvular disease have not resulted in a good long-term outcome. METHODS: We developed a novel "rasping procedure" using an electric rasper for debridement in rheumatic valvular diseases. Between April 1986 and December 1996, the rasping procedure was performed on the aortic valve (A-rasping) of 24 patients who exhibited moderate stenosis with mild regurgitation. Between June 1992 and December 1996, this procedure was performed on the mitral valve (M-rasping) of 12 patients who exhibited mitral stenosis with mild regurgitation. RESULTS: Among the 24 patients on whom A-rasping was performed, 4 patients did not show any improvement after the A-rasping procedure, and required valve replacement. In each of the remaining 20 cases, the transvalvular pressure gradient decreased, and regurgitation disappeared, or was reduced to a trivial level. In all 12 patients on whom M-rasping was performed, the transvalvular pressure gradient significantly decreased, orifice area significantly increased, and the regurgitation disappeared. Postoperative echocardiographic examinations were performed during a mean follow-up period of 110 months in the patients who received A-rasping, and that of 50 months in the patients who received M-rasping. A significant change in the valve requiring subsequent surgery was not seen in any of the patients. CONCLUSIONS: The rasping procedure is an effective technique for excising rheumatic valvular hypertrophic lesions. It resulted in good intermediate to long-term outcome.

[Clinical results of surgical repair for thoracic aortic aneurysms: intraoperative blood loss and morbidity].

Clinical results of 64 patients who underwent surgical repair for thoracic aortic aneurysms were studied, focusing on the relationship between intraoperative blood loss and postoperative morbidity. Operative mortality was 22% in the urgent repair group and 9% in the elective repair group. Deep hypothermia, operative death, postoperative complication were the factors which significantly correlated to the amount of intraoperative blood loss. In patients who received deep hypothermia, larger blood loss and higher incidence of mortality and morbidity were observed. There was a significant relationship between the lowest core temperature during cardiopulmonary bypass and the lowest platelet count. Intraoperative blood loss revealed as a strong risk factor to directly influence postoperative clinical outcome of thoracic aortic operation.