The effects of nitrous oxide on vitamin B12 and homocysteine levels in methyltetrahydrofolate reductase gene mutation.

BACKGROUND: We aimed to investigate the effects of nitrous oxide on plasma total homocysteine and vitamin B12 levels in patients with or without methyltetrahydrofolate reductase (MTHRF) gene mutation. METHODS: After obtaining the ethics committee approval and written informed consents of patients, 93 patients between 18-70 years of age scheduled for surgery anticipated to last 1-4 hours were enrolled in the study. Patients with contraindications for nitrous oxide use were excluded. Preoperatively, blood samples were obtained from all patients for the determination of MTHFR gene mutation. Anesthesia induction was achieved with 3 mg.kg-1 of propofol and 1 µg.kg-1 of fentanyl. Anesthesia maintenance was performed with sevoflurane and with a carrier gas composed of 40 % O2 and 60 % N2O. Venous blood samples were obtained after venous canulation, and 24 hours after extubation for the analysis of plasma total homocysteine, vitamin B12 levels. RESULTS: Eighty-one patients were included in the study. Postoperative vitamin B12 levels were found to be significantly lower when compared with their preoperative levels (p<0.05). It was found that MTHRF gene polymorphism had no significant effect on postoperative plasma total homocysteine and serum vitamin B12 levels (p>0.05). Postoperative plasma total homocysteine levels were found to be significantly different between patients with operation times under and over 3 hours (p=0.028). CONCLUSIONS: We conclude that MTHRF gene polymorphism had no significant effects on postoperative plasma total homocysteine levels. However, we found that homocysteine levels might rise in patients who received general anesthesia with nitrous oxide for longer than 3 hours (Tab. 7, Ref. 26).

A case report: Prostatic carcinoma with metastasis to the testicle.

Secondary testicular tumours are rare. We present a 54 years old patient with testicular metastasis from carcinoma of the prostate with a 7 years history of hormonotherapy and chemotherapy for advanced carcinoma.

A case report: renal metastasis of prostate cancer.

In this report, a rare case of renal metastasis of prostate cancer in a 55-year-old man is presented.

Selective management of high risk patients with an ascending aortic dilatation during aortic valve replacement.

BACKGROUND: The ascending aortic dilatation secondary to aortic valve disease may be a risk for rupture or dissection unless it is not corrected with a graft replacement during valve surgery. This additional procedure requires prolonged operation time that can be harmful for the critical patient. External reinforcement of diseased aorta is an old but simple method with debated long term results, providing brief duration and lower complication rate of the aneurysm operation for critically ill patients whose life expectancy is poor. METHODS: Twenty-two patients underwent aortic valve replacement and external aortic wrapping procedure in our clinic. All of the patients had severe associated risk factors to complicate the classical aortic graft replacement procedure. In this prospective clinical study, the follow-up period of the patients is 79.91 patient-years. RESULTS: There was no operative mortality. The average hospital stay was 8.6+/-2.6 days. There was no late death or cardiac morbidity. All of the patients were in NYHA Class 1 at postoperative 3rd month and thereafter. In CT scans the mean preoperative ascending aortic diameter was 5.12+/-0.38 cm while the mean diameter at 3rd month postoperatively was 3.19+/-0.25 cm. The reduction in diameter showed a significant difference (p<0.0001). The time related changes in luminal diameters showed some enlargement within the first year of the operation (p=0.03) that remained the same thereafter. CONCLUSIONS: The early results and 4 years follow-up suggest that the technique can be regarded as safe and effective in selected high risk patients.

Sternal cyanoacrylate gluing in mediastinitis. Effects on infection, stability and bone healing.

BACKGROUND: It is crucial to determine stability, histocompatibility and antibacterial properties of the cyanoacrylate used for sternal fixation. METHODS: Clinical study: in 17 cases of mediastinitis, debridement and rewiring the sternum, was applied as the treatment method (Group I). Eighteen cases of mediastinitis were treated with the same method added sternal cyanoacrylate gluing (Group II). A comparative study was done; the follow-up period was 36.7+/-4 and 18.5+/-6.9 months in Group I and II, respectively. Animal study: in 10 rats, upper sternotomy was done and the sternal bone was contaminated. Direct wound closure was done in 4 rats (Group A), in 6 animals, wounds were closed after applying cyanoacrylate in sternal split (Group B). In this prospective study, all rats alive were sacrificed at the 3rd and 8th weeks and sternums were examined histologically. RESULTS: Clinical study: in Group I, 6 patients required additional interventions due to recurrent sternal detachment and osteomyelitis (35.3%). In Group II neither osteomyelitis nor sternal detachment occurred, 3 patients required re-intervention related to cyanoacrylate histotoxicity. Hospital stay was higher in Group I than Group II (24.06+/-4.7 vs 14.16+/-3.98 days, respectively). Experimental study: all of the animals in Group A died of sepsis. In Group B all rats survived the procedure. At the 3rd week histologic evaluations showed that cyanoacrylate was not degraded, and no infection or foreign body reaction was observed. At the 8th week histologic examination showed that cyanoacrylate was completely degraded and replaced by connective tissue. CONCLUSIONS: Cyanoacrylate is effective in diminishing sternal wound complications and related cost and hospital stay of mediastinitis.

Accelerated atherosclerosis in tertiary syphilis and successful treatment with saphenous vein grafting--a case report.

A 48-year-old male patient having none of the known risk factors for atherosclerosis underwent coronary artery bypass graft (CABG) surgery because of double-vessel coronary artery disease. During the operation, the aorta, both internal thoracic arteries (L/R-ITA), and the femoral artery were sclerotic, and CABG was performed using only saphenous vein grafts. A diagnosis of tertiary syphilis had been confirmed by either microscopic or serologic tests. There were different degrees of sclerosis in different arteries of different sizes. The presence of coronary artery disease with no known atherosclerotic risk factors should include preoperative testing for connective tissue disorders, chronic inflammatory disease, and cold hemagglutinins, because of the possible use of obligatory deep hypothermia or total circulatory arrest due to a diseased ascending aorta.

Left ventricular endoaneurysmorrhaphy: effect on left ventricular size, shape and function.

Left ventricular (LV) endoaneurysmorrhaphy is a relatively new surgical procedure with excellent results. Forty-five patients underwent surgical repair of LV aneurysm with LV endoaneurysmorrhaphy from 1991 to 1995. The main indication for operation was angina pectoris (71%). Concomitant myocardial revascularization was performed in 97% of the patients. The operative mortality rate was 2.2%. Pharmacologic inotropic support was required in 31% and mechanical support in 15%. Mean echocardiographic ejection fraction improved from 29.6% preoperatively to 48.3% postoperatively (p <0.001). LV end-diastolic volumes were 195 +/- 63 and 118 +/- 44 ml before and after surgery (p <0.01). Intraoperative transesophageal echocardiography revealed normal or near-normal LV shape in all cases. The mean follow-up was 34.0 +/- 9.2 months (16-50 months) and 1 patient died 9 months postoperatively. We conclude that endoaneurysmorrhaphy improves LV geometry and function in patients with LV aneurysms and can be performed with low surgical risk even in patients with large aneurysms and severely depressed LV function. ........

Long-term prevention of atrial fibrillation after coronary artery surgery.

UNLABELLED: We researched the necessity of quinidine fumarate or acebutolol prophylaxis in patients in whom atrial fibrillation occurred in the postdischarge period and returned to sinus rhythm after coronary artery surgery. DESIGN: Prospective review. PATIENTS: Since 1992, 60 patients were chosen in whom atrial fibrillation occurred in early postoperative period. There were no significant differences between them and they were separated into 3 groups. In group I (20 patients) we did not give any drug, in group II (20 patients) quinidine fumarate was given and in group III (20 patients) acebutolol was given and patients were controlled for 90 days. RESULT: Atrial fibrillation occurred in one patient in group I, (5%), two in group II (10%) and two in group III (10%), (p < 0.05). Different from the other groups, atrial fibrillation was asymptomatic with low ventricular response in group III. CONCLUSIONS: There were no significant differences among three groups statistically, so we suggested that long-term prevention of atrial fibrillation with quinidine fumarate or acebutolol was not necessary after coronary artery surgery.

Postoperative use of aprotinin in cardiac operations: an alternative to its prophylactic use.

BACKGROUND: Aprotinin reduces blood loss after cardiopulmonary bypass. Although there can be little doubt about the efficacy of aprotinin, its safety has been questioned recently and is still under investigation. Because of the potential for complications and the high cost, a selective strategy limiting drug delivery to patients with established postoperative bleeding will be more reasonable. METHODS: In a prospective, randomized, double-blind trial we studied the effect of postoperative low-dose (2 million kallikrein inactivator units) aprotinin on blood loss and transfusion requirements in patients undergoing cardiopulmonary bypass. Fifty-seven patients were randomly assigned to two groups: aprotinin or placebo. RESULTS: The two groups were comparable in all demographic and surgical variables. Postoperative chest tube drainage was significantly less in the aprotinin group than in the placebo group (410 ml vs 696 ml, p < 0.01). The use of homologous blood products was significantly less in the aprotinin group than in the placebo group (0.4 +/- 0.5 unit vs 1.7 +/- 0.9 unit for packed red blood cells and 0.8 +/- 1.3 unit vs 2.3 +/- 1.6 unit for fresh frozen plasma). CONCLUSIONS: Our results suggest that postoperative aprotinin reduces blood loss and transfusion requirements and provides the opportunity to restrict its use selectively to patients with excessive postoperative bleeding.

Hypertension increases the contractions to sumatriptan in the human internal mammary artery.

BACKGROUND: The internal mammary artery is the graft of choice for myocardial revascularization. The tendency to spasm increases toward the distal end of the internal mammary artery, which is the portion generally used for anastomosis. The distal internal mammary artery is more pharmacologically responsive to 5-hydroxytryptamine and several other vasoconstrictor agents than its midsection. METHODS: We examined the effects of 5-hydroxytryptamine and a 5-hydroxytryptamine1-like receptor agonist sumatriptan on internal mammary artery segments (length, 3-4 mm) obtained from patients undergoing coronary artery bypass grafting. To unmask a 5-hydroxytryptamine1-like receptor-mediated contractile response, threshold concentrations of potassium chloride were used. RESULTS: 5-Hydroxytryptamine induced concentration-dependent contractions in all, quiescent and potassium chloride precontracted, preparations. Sumatriptan induced marked contraction in some of the quiescent internal mammary artery rings, whereas it elicited marked and concentration-dependent contractions in all of the preparations given a moderate tone by a threshold concentration of potassium chloride. The sensitivity to sumatriptan was higher in potassium chloride-precontracted distal arteries than it was for the quiescent distal segments. Additionally, the sensitivity to and the efficacy of sumatriptan were much more markedly potentiated by precontraction in the preparations taken from hypertensive patients. CONCLUSIONS: The more marked potentiation of the responses in arteries from hypertensive patients may be one of the factors influencing the patency rates.

5-HT1-like receptor-mediated contraction in the human internal mammary artery.

We wished to characterize the 5-hydroxytryptamine (5-HT) receptors mediating vasoconstriction in the human internal mammary artery (IMA). Segments of the IMA obtained from patients undergoing coronary by-pass surgery were suspended in an organ bath and exposed to 5-HT and sumatriptan (SUM), a 5-HT1-like receptor agonist, in the presence and absence of potassium chloride (KCl) and angiotensin II. 5-HT induced concentration-dependent contractions in all quiescent and pre-contracted preparations. SUM induced small contractions in 70% of quiescent IMA rings, whereas it elicited marked and concentration-dependent contractions in all of the preparations given a moderate tone by a threshold concentration of KCl and angiotensin II. The efficacy of SUM was higher in precontracted arteries. Concentration-effect curves (CEC) of 5-HT and SUM were not affected by the 5-HT3-receptor antagonist tropisetron (1 microM). The nonselective antagonist, methiothepin (30 nM), shifted the CEC of SUM to the right. 5-HT2A-receptor antagonist, ketanserin (1 microM) inhibited responses to 5-HT, whereas it affected only the responses to the smaller concentrations of SUM. When methiothepin (30 nM) was applied in the presence of ketanserin (1 microM), a further inhibition in the responses to 5-HT was observed. These results suggest that 5-HT1-like receptors mediate the contractile action of SUM and contribute to that of 5-HT in IMA.

Postoperative aprotinin: effect on blood loss and transfusion requirements in cardiac operations.

BACKGROUND: Aprotinin has been used increasingly to reduce postoperative blood loss in open heart operations. Although it was reported as safe in earlier studies, the overall safety of prophylactic use has been questioned recently. Because of the potential for complications and the high cost, it will be reasonable to use aprotinin more selectively in the postoperative period. METHODS: We prospectively studied the effect of postoperative low-dose aprotinin (2 million kallikrein inactivator units [280 mg]) on blood loss and transfusion requirements in patients undergoing cardiopulmonary bypass. Seventy-five patients were randomly assigned to three groups: prophylactic high-dose aprotinin (group 1), postoperative aprotinin (group 2), or a nonmedicated control group (group 3). RESULTS: The three groups were comparable in all demographic and operative variables. Postoperative chest tube drainage was significantly decreased in both aprotinin groups compared with that in the control group (295 mL in group 1 and 325 mL in group 2 versus 411 mL in group 3; p < 0.05). No significant difference was seen between the two aprotinin groups. The use of homologous blood products was significantly less in group 1 and group 2 than in group 3 (1.15 +/- 1.13 U and 1.35 +/- 1.30 U versus 2.55 +/- 1.09 U; p < 0.05). CONCLUSIONS: Our results suggest that postoperative aprotinin reduces blood loss and transfusion requirements comparably with prophylactic high-dose aprotinin. Thus, one can restrict its use to patients with excessive postoperative bleeding.

Transesophageal echocardiography in cardiac surgical emergencies.

The value and utility of transesophageal echocardiography (TEE) in unstable cardiac surgical patients have been assessed; 119 TEE studies were performed and evaluated in the emergency setting. The studies were performed in the cardiac surgical intensive care unit (n = 62) and in the operating room (n = 57). There were 81 men and 38 women with a mean age of 58.2 years. The indications for TEE were as follows: hypotension refractory to conventional treatment (n = 83); prosthetic or native valve dysfunction (n = 25); and suspected aortic dissection (n = 10). TEE provided valuable diagnostic information in 107 patients and was completely normal in 12 patients. Based on these results 22 patients had urgent surgical intervention without further studies. The average time to diagnosis was 11.2 minutes. No significant complications were noted. Our results suggest that TEE is highly diagnostic for most of the abnormalities responsible for hemodynamic instability in the perioperative period and facilitates decision making in cardiac surgical emergencies.

Intraoperative echocardiography: techniques and current applications.

Intraoperative echocardiography has opened new dimensions in the evaluation of cardiac surgical patients, and has contributed significantly to the improved surgical results. The use of intraoperative echocardiography has enabled the surgeon to image the working heart, to define the operative anatomy and physiology, and to evaluate the results immediately before the patients leave the operating room. This review summarizes the current status and applications of intraoperative echocardiography in the practice of cardiac surgery.

Vascular complications of intraaortic balloon pumping: unsheathed versus sheathed insertion.

Incidence of vascular complications in intraaortic balloon counterpulsation is still high despite major refinements in catheter design and techniques. One hundred twenty-six patients in whom intraaortic balloon pumping was attempted were divided into two groups on the basis of insertion technique. Group 1 included 77 patients in whom the conventional percutaneous insertion was used. In group 2 (n = 45 patients), a sheathless insertion technique was used. The overall vascular complication rate was 19.6%, with the lower limb ischemia as the most common complication. The vascular complication rate was 25.9% in group 1 and 8.8% in group 2 (p < 0.01). Lower limb ischemia was noted in 17 patients in group 1 and 3 patients in group 2 (p < 0.01). These results suggest that sheathless insertion of the intraaortic balloon pump catheter can minimize vascular complications. This technique will be especially useful in patients with peripheral vascular disease, in whom the likelihood of vascular complications is high.