A. Tulga Ulus

Bloodstream, Respiratory, and Deep Surgical Wound Infections after Open Heart Surgery

Abstract Nosocomial infections are one of the most feared complications after open heart surgery. A large retrospective study was conducted to evaluate the nature and scope of the problem. Between 1992 and 1998,9352 patients who had undergone open heart surgery were evaluated. Bloodstream infections, pneumonia, and deep sternal wound infections were included. Univariate and logistic regression analyses were conducted to identify the high‐risk patients that were likely to become infected. Three hundred forty‐six infections in 276 patients were diagnosed. Age, preoperative albumin level, banked blood requirement, duration of operation, diabetes mellitus, previous open heart surgery, moderate or severe pericardial adhesions, obesity, postoperative low cardiac output, and postoperative cerebrovascular accident were found to be significant in univariate and logistic regression analyses for infectious outcome. Univariate analysis also revealed additional significant factors: fresh frozen plasma requirement, duration of cardiopulmonary bypass and cross‐clamp, preoperative high levels of blood urea and glucose, presence of occlusive peripheral arterial disease, preoperative history of hypertension, and nasal carriage of Staphylococcus aureus. Methicillin resistant S. aureus was involved in 58.4% of the infections. Risk factors should be individualized for patients and every effort should be carried out to minimize infectious outcome. (J Card Surg 1998;13:252–259)

Effect of Mg2SO4 usage on spinal cord ischemia-reperfusion injury: Electron microscopic and functional evaluation

Objectives: To evaluate the effects of intravenous magnesium sulfate (Mg2SO4) administration on ischemia-reperfusion injury of the spinal cord. Material and Methods: Sixteen rabbits were randomly assigned to the control (group I, 8 rabbits) and the study group (group II, 8 rabbits). The abdominal aorta was clamped for a period of 30 min followed by a reperfusion period of 60 min. The animals in group II received 0.25 ml/kg/h Mg2SO4 intravenous infusion (15% Mg2SO4) throughout this procedure. The animals were then observed for 24 h after which their neurological states were evaluated and tissue samples obtained from the spinal cord were examined with electron microscopy. Results: Aortic pressure distal to the cross-clamp during the occlusion period was 9 ± 3 mm Hg in group I and 19 ± 6 mm Hg in group II. All animals in group I were paraplegic at the end of the study. In group II the neurological outcome of 1 animal was poor while the other 7 animals were neurologically in a good condition. Electron microscopic examinations of the spinal cord tissues of group I revealed severe injury but the ultrastructure was well preserved in group II. Conclusions: Intravenous Mg2SO4 administration may have protective effects on the ischemia-reperfusion injury of the spinal cord. We propose that Mg2SO4 may be an additional protective pharmacological agent in thoracal and thoracoabdominal aortic surgery.

Levosimendan Effect on Spinal Cord Ischemia-Reperfusion Injury Following Aortic Clamping

Abstract  Background and aim of the study: The new calcium sensitizer, levosimendan, not only acts as a positive inotropic agent but also, vasodilates both venules and arterioles. The aim of this experimental study was to investigate whether levosimendan has protective effects on spinal cord ischemia‐reperfusion injury. Material and Methods: Twelve New Zealand rabbits were enrolled in this study. In addition to the control group, levosimendan is administered to the experimental group with a loading dose of 12 μg/kg prior to ischemia over a 10‐minute period, followed by an infusion of 0.2 μg/kg/min during the ischemia period (30‐minutes). Following the neurologic evaluation at the 24th hour of reperfusion, lumbar spinal cords were removed in order to perform microscopic examination and malondialdehyde (MDA) and myeloperoxidase (MPO) measurements. Results: The mean Tarlov score of the levosimendan group (3.25) was higher than the control group (0.7) (p< 0.05). MDA level was found significantly lower in the levosimendan group when compared with the control group as 1.6 ± 0.4 nmol/gr and 189.3 ± 43.6 nmol/gr respectively (p < 0.05). MPO level was also found statistically significant when we compared levosimendan group with the control group. It was calculated as 11.3 ± 1.0 μ/gr tissue and 39.1 ± 16.9 μ/gr in the levosimendan and the control groups (p< 0.05). Light microscopic examination was carried out with tissue samples in the 24th hour of the reperfusion. Levosimendan group had better preservation with the microscopic appearance with respect to the control group. Conclusion: Levosimendan exhibits an important protection by means of neurological outcome, histopathological, and biochemical analysis for the ischemia‐reperfusion injury of the spinal cord following the aortic clamping.

Combined genetic mutations have remarkable effect on deep venous thrombosis and/or pulmonary embolism occurence

PURPOSE Although deep vein thrombosis and thromboembolic diseases differ among various races, they are still important in our day. The difficulties in treatment and following-up of these diseases are caused by secret genetic mutations rather than predisposing factors. METHODS Between January 2011 and May 2013, patients who were traced for deep vein thrombosis and/or pulmonary embolism were evaluated retrospectively. 84 patients (53.6% males and 46.4% females) were included in the study. Their family histories, predisposing factors and treatments were researched. Factor V Leiden (G 1691A), Factor II G20210A, Plasminogen Activator Inhibitor-Type 1 (4G/5G), and Methylene Tetrahydrofolate Reductase (C677T, A1298C) mutations were investigated from peripheral venous blood. RESULTS Among the genetic mutations we searched, the incidence of single mutation rate was observed at 11.9%, double mutation collocation at 44%, triple mutation collocation at 29.8%, quadruple mutation collocation at 13.1%, and finally, quintuplet mutation collocation at 1.2%. Our approximate mutation number was found as 2.47 ± 0.91. CONCLUSION We observed that multiple mutations were high in number compared to single genetic mutations. The patients who have multiple mutations should be more in the front line considering their diagnosis, treatment and following up, and also in terms of decreasing mortality, morbidity and recurrence.

Acute mechanical valve thrombosis of the St. Jude medical prosthesis.

Abstract From 1986 to 1996, 2585 patients underwent valve replacement with the St. Jude medical prosthesis. Sixty experienced mechanical valve thrombosis. Seventeen of 60 patients (28.3%) had isolated aortic valve replacements, 33 had isolated mitral valve replacements (55%), and 10 had double valve replacements (16.7%) (aortic and mitral valve replacement). All patients who underwent reoperation for mechanical valve thrombosis were functional Class III or IV. Against medical advice, systemic anticoagulation with warfarin sodium had been discontinued or used only intermittently. Thus, anticoagulant activity was not adequate. The diagnosis of thrombosis was made by clinical examination, laboratory findings, and echocardiography and cineradiography. Of the 60 patients, 9 patients died early after surgery or before discharge. Most of the deaths were attributed to low cardiac output. The overall hospital mortality was 15%. The overall 10‐year actuarial survival rate was 82.8 ± 1.6%. In our study, reoperation for thrombosed mechanical prosthesis was not an independent parameter determining mortality. Age was the only statistically important hospital mortality predictor. Of this group, 90% suffered mechanical valve obstruction within the first 5 years after operation. These results suggest that valve re‐replacement appears to be a suitable surgical treatment for thrombosis of mechanical prosthetic valves, especially in the young. In these patients subsequent anticoagulation management is necessary.

Surgical and histopathological effects of topical Ankaferd® hemostat on major arterial vessel injury related to elevated intra-arterial blood pressure.

OBJECTIVE The aim of this study was to assess the surgical and histopathological hemostatic effects of topical Ankaferd blood stopper (ABS) on major arterial vessel injury related to elevated intra-arterial blood pressure in an experimental rabbit model. METHODS The study included 14 New Zealand rabbits. ABS was used to treat femoral artery puncture on 1 side in each animal and the other untreated side served as the control. Likewise, for abdominal aortic puncture, only 50% of the aortic injuries received topical liquid ABS and the others did not (control). The experiment was performed under conditions of normal arterial blood pressure and was repeated with a 50% increase in blood pressure. Histopathological analysis was performed in all of the studied animals. RESULTS Mean bleeding time in the control femoral arteries was 105.0±18.3 s, versus 51.4±9.8 s (p<0.05) in those treated with ABS. Mean blood loss from the punctured control femoral arteries was 5.0±1.5 mg and 1.6±0.4 mg from those treated with ABS (p<0.05). Histopathological examination of the damaged arterial structures showed that ABS induced red blood cell aggregates. CONCLUSION ABS administered to experimental major arterial vessel injury reduced both bleeding time and blood loss under conditions of normal and elevated intra-arterial blood pressure. ABS-induced erythroid aggregation was prominent at the vascular tissue level. These findings will inform the design of future experimental and clinical studies on the anti-bleeding and vascular repairing effects of the novel hemostatic agent ABS.

Aortic Valve Replacement With the St. Jude Medical Prosthesis and Fixed Dose Anticoagulation

Abstract Over a 10‐year period, between 1986 and 1996, 865 patients underwent primary aortic valve replacement (AVR) with the St. Jude Medical mechanical prosthesis. Patients who had undergone valve replacement with a different type of prosthesis previously were excluded from this study. Patient age ranged from 11 to 79 years. The mean age was 42.9 ± 14.54. The gender distribution was 396 men (45.8%) and 469 women (54.2%). All patients received 2.5 mg/day Coumadin after extubation. A combination of the antiagregant therapy (Dypridamole 3 × 75 mg/day, Asprine 100 mg/day) was added after removal of the chest tubes. The dosage of Coumadin was maintained constant regardless of the prothrombin time (PT) or cardiac rhythm. There were 101 valve‐related complications (4.2% per patient year [ppy]) occurring in the late follow‐up period. Of these complications; 38 were anticoagulant‐related hemorrhage (1.58% ppy), 3 were paravalvular leak (0.12% ppy), and 36 were thromboembolism (1.4% ppy). There were 24 reoperations (0.99% ppy) and 17 late deaths. The linearized late mortality rate was 0.7% ppy. Long‐term survival estimates at 5 and 10 years were 97.14 ± 0.82% and 94.86 ± 1.54%, respectively. We conclude from the data that the St. Jude Medical valve may allow the use of a low level of anticoagulation. This study shows that fixed dose oral anticoagulation does not increase the rate of thromboembolism in patients with the St. Jude aortic valve. This protocol does not result in reduction of bleeding complications, however.

Iloprost added to the cardioplegic solutions improves myocardial performance.

A total of 12 mongrel dogs were divided into two equal groups. Six animals received IIoprost and the other 6 animals did not receive any additional treatment. In the Iloprost group, Iloprost was added to the cardioplegic solution (25 ng). Also, Iloprost was used (10 ng/kg/min.) 5 min. before and after cross-clamping. All cardiac output and biochemical measurements were evaluated before cross-clamp and 15 min., 1 h, and 4 h after cross-clamp. The measured dp/dt shows that the hearts treated with Iloprost preserved left ventricular function. Comparison of contractility indices between the groups revealed that contractile recovery was 59% in the control group and 71% in the Iloprost group (p < 0.05). Tumor necrosis factor (TNF) alpha level was significantly elevated in the control group (p < 0.001). Its level was 22.2 +/- 2.2 pg/mL in the control group and 13.8 +/- 1.0 pg/mL in the Iloprost group. E- and P-selectin levels were elevated in the control group (p < 0.001). ICAM-1 level was also elevated in the control group. ICAM-1 level was 17.7 +/- 1.8 ng/mL in the control group and 8.5 +/- 1.8 ng/mL in the Iloprost group. The Iloprost that was added to the cardioplegic solution and low dose administration during the pre- and post-ischemic period inhibits the toxic mediator release from endothelium-leukocyte interaction and reduces the severity of ischemia-reperfusion injury.

Which type of conditioning method protects the spinal cord from the ischemia-reperfusion injury in 24 hours?

Objective This study was designed to test the effects of different types of preconditioning and postconditioning methods on spinal cord protection following aortic clamping. Methods The animals (rabbits) were divided into sham-operated, ischemic preconditioning, remote ischemic preconditioning, simultaneous aortic and ischemic remote preconditioning, and ischemic postconditioning groups. After neurological evaluations, ultrastructural analysis and immunohistochemical staining for caspase-3 were evaluated after 24 h following ischemia. Results The neurological outcomes of the remote ischemic preconditioning (4.2 ± 0.4) and ischemic postconditioning (4.6 ± 0.8) groups were significantly improved when compared with the ischemia group (2.2 ± 04). The immunohistochemical analysis revealed that the lowest percentage of apoptosis was in-group ischemic preconditioning at 12.5 ± 30.6%. In the comparison of intracellular edema in an ultrastructural analysis, the ischemic preconditioning and ischemic postconditioning groups had significantly lower values than the ischemia group. Conclusion The conditioning methods attenuate ischemia–reperfusion injury for spinal cord injury. Ischemic and remote preconditioning and also postconditioning methods are simple to perform and inexpensive.

Effect of Conditioning on Visceral Organs during Indirect Ischemia/Reperfusion Injury

BACKGROUND The mortality and morbidity rates of even extensive thoracoabdominal replacement have improved markedly in recent years. We investigated the effects of a temporary occlusion of the aorta as a direct precondition and temporary occlusion of the axillary artery for remote preconditioning to determine any effects that preconditioning may have on indirect (nonischemic) injuries to visceral organs (indirect effects of remote ischemia/reperfusion injury). METHODS Thirty-seven New Zealand white rabbits were divided into five groups: controls (sham-operated; group 1); direct ischemia to the infrarenal aorta without preconditioning (group 2); direct ischemic preconditioning to the infrarenal aorta (group 3); remote ischemic preconditioning before clamping the infrarenal aorta (group 4); and simultaneous direct aortic and remote ischemic preconditioning before the clamping and during clamping of the infrarenal aorta (group 5). We used a 30-minute ischemia period for aortic occlusion for spinal cord ischemia/reperfusion. The axillary artery was used for remote preconditioning. After 24 hours, tissue specimens of the internal organs were obtained. RESULTS Myocardial congestion was the main pathology detected in all groups. Histopathologic evaluation of tissue samples taken from the hearts showed no significant differences in terms of the degree of polymorphonuclear leukocyte (PMNL) infiltration and edema between the groups. Lung congestion and pneumonic cell infiltration were detected in all the groups. Pneumonic cell infiltration was significantly high in groups 2 and 3. Cell infiltration was lowest in group 4 at 71.4% of normal values, which differed from the normal values of 25-33.3% in the other groups (P < 0.05). Although there is a difference between the groups in case of renal congestion, there is not any difference as tubular damage and PMN. There was a significant difference with regard to renal congestion between groups 2 and 3. Renal congestion was normal in 80% of the kidneys in group 3. This differed from the normal values observed in the other groups (14.3-57.1%, P < 0.05). Liver congestion was detected in all groups. CONCLUSIONS Different preconditioning methods may play an important role in distinct organ injuries during aortic cross-clamping. The visceral organs that exhibited positive and constructive results with direct and remote preconditioning included the lungs and kidneys during indirect ischemia/reperfusion injury. Remote ischemic conditioning was determined to be especially advantageous as a protection method, due to the fact that it is easy to use and effective for indirect ischemia/reperfusion injury.