Deep pericardial sling versus lateral pericardial sutures in off-pump coronary artery bypass surgery.

AIM: The aim of this study was to evaluate the safety and efficacy of deep pericardial sling (DPS) versus lateral pericardial sutures (LPSs) for heart stabilization and adequate coronary artery exposure during off-pump coronary artery bypass surgery (OPCAB). METHODS: One surgeon employed in 101 consecutive patients a series of four to six 2-0 polyglactin sutures placed laterally between the left phrenic nerve and the left pulmonary veins (LPS). Two other surgeons used in 104 consecutive patients a single 0-0 braided silk suture with moistened gauze placed in the oblique sinus of the posterior pericardium, between the inferior vena cava and the right lower pulmonary vein (DPS). RESULTS: One conversion to beating heart surgery with cardiopulmonary bypass support occurred in each study group. No patient in the LPS group was converted to DPS technique. The use of LPSs allowed a number of distal anastomoses somewhat higher than the DPS technique (4.1+/-1.1 vs. 3.7+/-1.1, P=0.02). Postoperative results were similar in both study groups. A lower incidence of postoperative low-cardiac output syndrome and of prolonged need of inotropes has been observed in the LPS group, but the difference failed to reach statistical significance. One patient in the LPS group had postoperative left phrenic nerve palsy. One patient in the DPS group suffered of intraoperative bleeding secondary to rupture of the inferior vena cava likely related to placement of DPS, which was successfully repaired. CONCLUSION: LPS technique is as effective as DPS technique and allows complete revascularization with a postoperative outcome similar to the latter technique.

Risk of retinal microembolism after off-pump and on-pump coronary artery bypass surgery.

AIM: In order to investigate the neuroprotective efficacy of off-pump coronary artery bypass surgery (OPCAB) over conventional on-pump coronary artery bypass surgery (CCAB), we have performed a prospective randomized study evaluating retinal circulation changes after OPCAB and CCAB. METHODS: Twenty patients were randomized to OPCAB or CCAB. Retinal fluorescein angiography and 60 degrees black-and-white as well as color fundus photographs of both eyes of each patient were taken 1 to 24 h before and 5 to 6 days after the operation. RESULTS: Patients undergoing OPCAB had more severely stenosed carotid arteries (P=0.075), higher incidence of slightly diseased ascending aorta (P=0.087) and higher Northern New England Cardiovascular Study Group stroke risk score (P=0.075). Neither stroke nor transient ischemic attack occurred postoperatively in these patients. Inferotemporal retinal arterial embolization and microinfarction was detected in one patient after CCAB, but in none of the OPCAB group. CONCLUSION: The risk of retinal embolism can be minimized by the use of OPCAB and, most likely, by adequate epiaortic ultrasound scanning of the ascending aorta and avoiding clamping in case of severely diseased aorta.

Off-pump versus on-pump coronary artery bypass surgery in high-risk patients (EuroSCORE >/= 6).

OBJECTIVE: The aim of this study was to review the results of off-pump (OPCAB) versus conventional on-pump coronary artery bypass surgery (CCAB) in high-risk patients. METHODS: In a cohort of patients with an additive EuroSCORE >/= 6, 67 underwent OPCAB and 112 underwent CCAB. RESULTS: Thirty-day postoperative death and stroke rates were 7.5 % and 6.0 % for the OPCAB group, and 5.4 % ( P = 0.75) and 8.0 % ( P = 0.77) for the CCAB group, respectively. No significant differences were observed for other major outcome endpoints other than cardiac troponin I (OPCAB: 117 +/- 428 ng/ml vs. CCAB: 58 +/- 99 ng/ml, P = 0.028), a result which was probably due to preoperative massive myocardial infarction in two very high-risk patients who underwent OPCAB. A similar outcome was also observed among propensity score-matched pairs. Congestive heart failure ( P = 0.006, OR: 6.366, 95 % CI: 1.682 - 24.093) and baseline cardiac index ( P = 0.018, OR: 0.171, 95 % CI: 0.040 - 0.735) were independent predictors of 30-day postoperative mortality. CONCLUSIONS: OPCAB can be safely performed in high-risk patients with results as satisfactory as those achieved with CCAB.

Lower limb ischemic complications after the use of arterial puncture closure devices.

We report three cases of lower limb ischemia occurring after the use of arterial puncture closure devices (APCDs). In two patients, who have undergone percutaneous angioplasty of lower limb arteries, the Angio-Seal APCD led to thrombosis of the common femoral artery. In another patient who has undergone coronary angiography, this device has led to dissection of the common femoral artery. Since these observations seem to not be merely sporadic, radiologists and cardiologists as well as vascular surgeons should be aware of their possible occurrence in order to avoid these complications and to provide promptly an adequate treatment.

Extracranial internal carotid and vertebral artery dissections: angiographic spectrum, course and prognosis.

We reviewed the clinical and radiological findings of 93 consecutive patients with 111 extracranial internal carotid (ICAD) and vertebral artery (VAD) dissections and one concomitant intracranial VAD; 83% of the patients had unilateral and 17% multiple vessel dissections. The diagnosis was made by intra-arterial digital subtraction angiography in 92 patients and MR angiography in one. Follow-up angiography was performed in 77 cases (83%): of 49 initially stenotic arteries, 40 became completely or almost completely normal, while three showed slight improvement. Of 30 initially occluded arteries, nine had completely or partly recanalised. Of 12 pseudoaneurysms eight were unchanged at follow-up. The proximal vertebral artery was involved as often as the C1-C2 level. Recurrences were rare: a new dissection in another vessel was found in three patients. Kinking or coiling was found in 23% of the dissected internal carotid arteries.

Myocardial preservation during coronary surgery with and without cardiopulmonary bypass.

BACKGROUND: There is increased interest in coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB), although the preservation of the myocardium under such circumstances has not been properly investigated. The aim of this randomized study was to compare the changes in myocardial metabolism during CABG with and without CPB. METHODS: Myocardial energy metabolism and tissue injury during CABG was monitored in a series of 22 patients (11 with and 11 without CPB). RESULTS: The maximum myocardial lactate production was significantly higher (p = 0.02) in the group operated with CPB (0.56 mmol/L) than without it (0.17 mmol/L). A similar phenomenon was seen in the transcardiac pH differences (0.085 and 0.034 with and without CPB, p = 0.007). The postoperative peak values of creatine kinase-MB mass (15.1 vs 6.3 microg/L) and troponin I (13.8 vs 5.2 microg/L) were significantly higher (p < 0.001 and p = 0.008) with than without CPB. CONCLUSIONS: CABG on a beating heart is associated with better myocardial energy preservation and less myocardial damage compared with conventional CABG with CPB and intermittent antegrade mild hypothermic blood cardioplegia.

Reversible ischemic inhibition of F(1)F(0)-ATPase in rat and human myocardium.

The physiological role of F(1)F(0)-ATPase inhibition in ischemia may be to retard ATP depletion although views of the significance of IF(1) are at variance. We corroborate here a method for measuring the ex vivo activity of F(1)F(0)-ATPase in perfused rat heart and show that observation of ischemic F(1)F(0)-ATPase inhibition in rat heart is critically dependent on the sample preparation and assay conditions, and that the methods can be applied to assay the ischemic and reperfused human heart during coronary by-pass surgery. A 5-min period of ischemia inhibited F(1)F(0)-ATPase by 20% in both rat and human myocardium. After a 15-min reperfusion a subsequent 5-min period of ischemia doubled the inhibition in the rat heart but this potentiation was lost after 120 min of reperfusion. Experiments with isolated rat heart mitochondria showed that ATP hydrolysis is required for effective inhibition by uncoupling. The concentration of oligomycin for 50% inhibition (I(50)) for oxygen consumption was five times higher than its I(50) for F(1)F(0)-ATPase. Because of the different control strengths of F(1)F(0)-ATPase in oxidative phosphorylation and ATP hydrolysis an inhibition of the F(1)F(0)-ATPase activity in ischemia with the resultant ATP-sparing has an advantage even in an ischemia/reperfusion situation.

Myocardial metabolism and hemodynamics during coronary surgery without cardiopulmonary bypass.

BACKGROUND: Although renewed interest has recently been shown in coronary artery bypass grafting without cardiopulmonary bypass, no reports are available on myocardial metabolism and hemodynamics during temporary coronary occlusion and rotation of the contracting heart. METHODS: Changes in myocardial energy metabolism and hemodynamics were monitored in 12 patients undergoing elective coronary artery bypass grafting without cardiopulmonary bypass, and the postoperative efflux of creatine kinase-MB mass and troponin T were also determined. RESULTS: There was a significant increase in myocardial production of ATP degradation products (p = 0.026) and lactate (p = 0.004) during the operation. Myocardial oxygen extraction decreased (p = 0.012) in correlation with use of the short-acting beta-blocker, esmolol (r = -0.71). Apart from a decrease in mean arterial blood pressure (p = 0.002), there were no significant hemodynamic changes during the operation. The overall postoperative troponin T and creatine kinase-MB mass changes remained nonsignificant during the first two postoperative days. One patient had a myocardial infarction, diagnosed by electrocardiography, on the second postoperative day, but otherwise there were no major complications. CONCLUSIONS: Coronary artery bypass grafting without cardiopulmonary bypass seems to be well tolerated as only minor changes in myocardial energy metabolism and hemodynamics are observed during the operation.

Multiple endocrine neoplastic-associated thymic carcinoid tumour in close relatives: octreotide scan as a new diagnostic and follow-up modality. Two case reports.

Thymic carcinoid tumours constitute less than 1% of all carcinoids, and differ markedly from true thymomas in natural history, morphology, prognosis and therapeutic options. New clinical and diagnostic modalities are described in two brothers with thymic carcinoid associated with multiple endocrine neoplasia syndrome. Octreotide scintigraphy proved useful for diagnosis and follow-up, and somatostatin receptor positivity may provide new prospects for treatment of non-resectable or recurrent tumour.

Myocardial protection during antegrade versus retrograde cardioplegia.

BACKGROUND: It has been suggested that the right ventricular myocardium is suboptimally protected during retrograde blood cardioplegia. METHODS: Twenty patients undergoing an elective coronary bypass procedure were randomized to receive antegrade or retrograde mild hypothermic blood cardioplegia. Transventricular differences in oxygen extraction, lactate production, and pH were monitored during aortic cross-clamping, and myocardial biopsy specimens were taken from both ventricles before cannulation and 15 minutes after aortic declamping for analysis of adenine nucleotides and their breakdown products. The extent of myocardial injury was estimated by monitoring postoperative leakage of troponin T and the MB isoenzyme of creatine kinase. Hemodynamic recovery and postoperative complications were noted. RESULTS: The preoperative characteristics of the two groups were similar. Oxygen extraction and lactate production in the right ventricular myocardium were higher in the retrograde group. In this group, the right ventricle also extracted more oxygen and produced more lactate and acid than did the left ventricle. Tissue levels of adenine nucleotides tended to decrease in both ventricles during operation, with no differences between them. The level of adenosine catabolites did increase somewhat in the right ventricular myocardium of the retrograde cardioplegia group after aortic declamping. There was a tendency for more prominent efflux of troponin T and the MB isoenzyme of creatine kinase in the retrograde group. Nevertheless, the postoperative course was uneventful in both groups. CONCLUSIONS: Retrograde mild hypothermic blood cardioplegia leads to metabolic changes compatible with right ventricular ischemia. Nevertheless, tissue levels of high-energy phosphates are well preserved, and the postoperative course seems to be unproblematic. Care should be taken when retrograde normothermic blood cardioplegia is provided for patients with right ventricular hypertrophy, poor right ventricular function, or severe preoperative myocardial ischemia.

Normothermic retrograde blood cardioplegia with or without preceding ischemic preconditioning.

BACKGROUND: Preconditioning has been suggested as the most powerful mechanism of myocardial protection against prolonged ischemia. However, whether preconditioning offers additional benefits over cardioplegia during coronary artery bypass grafting is not known. METHODS: Thirty patients undergoing coronary artery bypass grafting were randomized into two groups. After aortic cross-clamping, group 1 received antegrade blood and blood cardioplegia followed by normothermic retrograde blood cardioplegia (controls), whereas group 2 patients were subjected to 5 minutes of global ischemia followed by reperfusion with antegrade and retrograde blood cardioplegia (preconditioned). The transcardiac differences in oxygen saturation, pH, and lactate were measured during cardiopulmonary bypass. Myocardial biopsy specimens were taken from half of the patients for adenosine triphosphate determination. The extent of myocardial injury was estimated by monitoring the postoperative leakage of creatine kinase-MB and troponin T. Immediate hemodynamic recovery and postoperative complications were also observed. RESULTS: The 5-minute preconditioning induced marked lactate and acid production, and myocardial adenosine triphosphate levels tended to decrease. The heart continued to produce lactate and acid during retrograde cardioplegia, but the transcardiac pH and lactate differences were similar in both groups. Adenosine triphosphate level measured at the end of the cross-clamp period was decreased to a half and one third of the preclamp values in the control and preconditioned groups, respectively. The postoperative creatine kinase-MB and troponin T effluxes tended to be more elevated in the preconditioned group, yet hemodynamic recovery and the number of postoperative complications were similar in both groups. CONCLUSIONS: The results show that a 5-minute preconditioning ischemia does not offer any additional benefits over normothermic retrograde blood cardioplegia during coronary artery bypass grafting.

Surgical and long-term outcome of graft replacement of aneurysms of the descending thoracic aorta. Analysis of 28 consecutive cases.

A consecutive series of 28 patients operated on at the Oulu University Hospital during the years 1974-1994 for aneurysms of the descending thoracic aorta is presented. Twenty-five cases were elective and three were operated on as emergencies. Their mean age was 58 years. During the aortic cross-clamp, circulatory support of the lower body, was used in 27 cases as follows: a direct aorto-femoral shunt without a pump (12/28), left-heart bypass (11/28) or femoro-femoral perfusion (4/28). Hospital mortality was 14% (4/28). One patient with a ruptured aneurysm died of renal failure, but there were no other renal complications. None had paraplegia postoperatively. Three had symptoms of paraparesis, but only one of them had a slight permanent discomfort while walking. The mean follow-up time was 100 months, range 2-242 months. Late actuarial survival including hospital mortality, was 65% at 5 years and 41% at 10 years, reflecting the generalized aortic disease with a high risk of very late rupture (4) and other manifestations of atherosclerosis with myocardial infarction (6) or cerebral atherosclerosis (1), the remaining late deaths being unrelated. The efficacy of lower body circulatory support in avoiding peroperative renal and spinal cord ischaemic complications is demonstrated.

Repair of an aneurysm of the left main coronary artery.

Coronary artery aneurysms are rare, especially in the left main coronary artery. Coronary artery aneurysms may rupture or cause myocardial infarction. There are only a few reports of coronary artery aneurysms of the left main coronary artery treated surgically. We report a case in which an arterial graft from the internal iliac (hypogastric) artery was used for the reconstruction of a congenital coronary artery aneurysm of the left main coronary artery. After a follow-up of 5 years, the patient is well and in good condition.

Cerebral haemorrhage after carotid endarterectomy.

Cerebral stroke is a serious complication related to carotid endarterectomy (CEA), being most frequently caused by thromboembolic events and less frequently on account of cerebral haemorrhage. The present series comprised five out of 857 (0.6%) patients who had undergone CEA at Oulu University Hospital between the years 1974 and 1993 and suffered a postoperative stroke four to 13 days after surgery due to intracerebral haemorrhage (IH). Preoperatively, all these patients were neurologically intact, with transient ischaemic attacked (TIA) as the main indication for CEA. All five patients had a history of arterial hypertension treated adequately preoperatively, and one patient had high blood pressure levels after surgery. Critical ipsilateral stenosis of the internal carotid artery (> 90%) was detected in the preoperative angiogram in all five cases. The primary outcome after CEA was uneventful in every case, without any signs of neurological deficiency. The symptoms, comprising severe headache, convulsions and/or hemiparesis occurred suddenly four to 13 days (mean seven days) after CEA. The diagnosis of IH was based on computed tomography (CT) findings. All five patients were treated conservatively. Three of them died. We conclude that even normotensive, neurologically intact patients without demonstrable cerebral infarction or postoperative hypertension may suffer cerebral haemorrhage after the relief of high-grade carotid stenosis. The role of possible insufficiency of the autoregulatory mechanisms of the cerebral vasculature on account of long-standing critical stenosis of the internal carotid artery and subsequent uncontrolled hyperperfusion following CEA are discussed.

De Vega's annuloplasty for tricuspid regurgitation.

A total of 337 patients underwent a mitral or combined mitral and aortic valve operation at the Oulu University Hospital between 1986 and 1992. Of these, 30 (8.9%) patients had De Vega's semicircular annuloplasty performed because of tricuspid regurgitation (TR) which was considered functional in nature. There were five (16.6%) early and seven (23.3%) late deaths during the follow-up period of 10 to 71 months. The preoperative mean New York Heart Association (NYHA) functional class was 3.4, and at follow-up 13 (76.5%) of the survivors were in NYHA CLass I or II. The actuarial survival rate was 37.6% at five years. All the survivors were evaluated echocardiographically and the TR was considered mild in 56.3%, moderate in 25.0% and severe in 18.7% of the cases. Tricuspid annuloplasty using De Vega's semicircular suture technique is a simple and effective procedure in patients with mild to moderate regurgitation. In patients with massive regurgitation, which is usually associated with a massively dilated tricuspid annulus and pulmonary hypertension, annuloplasty should be reinforced using a ring technique. Tricuspid valve replacement is hardly ever needed in the treatment of functional tricuspid regurgitation.