Feasibility and safety of delivering xenon to patients undergoing coronary artery bypass graft surgery while on cardiopulmonary bypass: phase I study

BACKGROUND: Postoperative neurocognitive deficit is prevalent after cardiac surgery. Xenon may prevent or ameliorate acute neuronal injury, but it also may aggravate injury during cardiac surgery by increasing bubble embolism. Before embarking on a randomized clinical trial to test the safety and efficacy of xenon for postoperative neurocognitive deficit, we undertook a phase I study to investigate the safety of administering xenon to patients undergoing coronary artery bypass grafting while on cardiopulmonary bypass and to assess the practicability of our xenon delivery system. METHODS: Sixteen patients scheduled for coronary artery bypass grafting surgery with hypothermic cardiopulmonary bypass gave their informed consent to participate in an open-label dose-escalation study (0, 20, 35, 50% xenon in oxygen and air). Xenon was delivered throughout surgery using both a standard anesthetic breathing circuit and the oxygenator. Gaseous and blood xenon partial pressures were measured five times before, during, and after cardiopulmonary bypass. Middle cerebral artery Doppler was used to assess embolic load, and major organ system function was assessed before and after surgery. RESULTS: Middle cerebral artery Doppler showed no evidence of increased emboli with xenon. Patients receiving xenon had no major organ dysfunction: Troponin I and S100beta levels tended to be lower in patients receiving xenon. Up to 25 l xenon was used per patient. Xenon partial pressure in the blood tracked the delivered concentration throughout. CONCLUSIONS: Xenon was safely and efficiently delivered to coronary artery bypass grafting patients while on cardiopulmonary bypass. Prevention of nervous system injury by xenon should be tested in a large placebo-controlled, randomized clinical trial.     

Combined use of off-pump techniques and a sutureless proximal aortic anastomotic device reduces cerebral microemboli generation during coronary artery bypass grafting

OBJECTIVE: Intraoperative cerebral microemboli are associated with the development of postoperative stroke and neurocognitive decline in patients undergoing coronary artery bypass grafting. Although cardiopulmonary bypass is responsible for the generation of a significant number of such emboli, the elimination of cardiopulmonary bypass alone has not been conclusively shown to improve neurocognitive outcome. The current study was performed to determine the effects of combined off-pump coronary artery bypass grafting and sutureless proximal aortic anastomotic techniques on the generation of intraoperative cerebral microemboli compared with standard coronary artery bypass grafting techniques of cardiopulmonary bypass and hand-sewn proximal anastomoses. METHODS: Fifty-three patients underwent off-pump coronary artery bypass grafting by using the sutureless Symmetry aortic connector device (St Jude Medical, St Paul, Minn) for all proximal anastomoses. Eighteen of these patients received intraoperative transcranial Doppler ultrasonography to determine right- and left-sided cerebral microembolic counts. These results were compared with those obtained from a similar group of 17 patients undergoing standard coronary artery bypass grafting, in whom cardiopulmonary bypass and hand-sewn proximal anastomoses were used. RESULTS: Our use of the proximal anastomotic device in patients undergoing coronary artery bypass grafting was safe, with no aortic complications, postoperative strokes, or in-hospital deaths. Microembolic counts to both the right and left cerebral circulation were significantly reduced in the patients undergoing off-pump coronary artery bypass grafting (right = 21.9 +/- 20.7 emboli, left = 24.9 +/- 19.2 emboli) compared with those in patients undergoing standard coronary artery bypass grafting (right = 181.6 +/- 85.3, left = 189.9 +/- 60.401, P <.0001). CONCLUSIONS: Our use of a sutureless proximal anastomotic device during off-pump coronary artery bypass grafting is safe and significantly decreases cerebral microembolism when compared with standard coronary artery bypass grafting with cardiopulmonary bypass and hand-sewn anastomoses. Long-term follow-up is needed to determine the effects of this technical strategy on neurocognitive outcome.     

Solid and gaseous cerebral microembolization during off-pump, on-pump, and open cardiac surgery procedures

BACKGROUND: Neurocognitive dysfunction remains a limitation of cardiac surgery with cardiopulmonary bypass. Intraoperative cerebral microembolization is believed to be one of the most important etiologic factors. Using a new generation of transcranial Doppler ultrasonography, we compared the number and nature of intraoperative microemboli in patients undergoing on-pump and off-pump cardiac surgery procedures. METHODS: Bilateral continuous transcranial Doppler monitoring of the middle cerebral arteries was performed in 45 patients (15 off-pump coronary artery bypass grafting, 15 on-pump coronary artery bypass grafting, and 15 open cardiac procedures). All recordings were performed using a multi-range, multifrequency system to allow both measurement of the number and discrimination of the nature of microemboli in the 3 different groups. RESULTS: The median number (interquartile range) of microemboli in the off-pump coronary artery bypass grafting, on-pump coronary artery bypass grafting, and open procedure groups were 40 (28-80), 275 (199-472), and 860 (393-1321), respectively (P <.01). Twelve percent of microemboli in the off-pump coronary artery bypass grafting group were solid compared with 28% and 22% in the on-pump coronary artery bypass grafting and open procedure groups, respectively (P <.05). In the on-pump groups, 24% of microemboli occurred during cardiopulmonary bypass, and 56% occurred during aortic manipulation (cannulation, decannulation, application, and removal of crossclamp or sideclamp). CONCLUSIONS: Cerebral microembolization is significantly reduced with avoidance of cardiopulmonary bypass. The majority of microemboli occurring during cardiac surgery are gaseous, with a higher proportion of solid microemboli in the on-pump group, and may have a different significance for cerebral injury than solid microemboli. The ability to reliably discriminate gas and solid microemboli may have an important role in the implementation of neuroprotective strategies.     

Effects of extreme hemodilution during cardiac surgery on cognitive function in the elderly

BACKGROUND: Strategies for neuroprotection including hypothermia and hemodilution have been routinely practiced since the inception of cardiopulmonary bypass. Yet postoperative neurocognitive deficits that diminish the quality of life of cardiac surgery patients are frequent. Because there is uncertainty regarding the impact of hemodilution on perioperative organ function, the authors hypothesized that extreme hemodilution during cardiac surgery would increase the frequency and severity of postoperative neurocognitive deficits. METHODS: Patients undergoing coronary artery bypass grafting surgery were randomly assigned to either moderate hemodilution (hematocrit on cardiopulmonary bypass >or=27%) or profound hemodilution (hematocrit on cardiopulmonary bypass of 15-18%). Cognitive function was measured preoperatively and 6 weeks postoperatively. The effect of hemodilution on postoperative cognition was tested using multivariable modeling accounting for age, years of education, and baseline levels of cognition. RESULTS: After randomization of 108 patients, the trial was terminated by the Data Safety and Monitoring Board due to the significant occurrence of adverse events, which primarily involved pulmonary complications in the moderate hemodilution group. Multivariable analysis revealed an interaction between hemodilution and age wherein older patients in the profound hemodilution group experienced greater neurocognitive decline (P = 0.03). CONCLUSIONS: In this prospective, randomized study of hemodilution during cardiac surgery with cardiopulmonary bypass in adults, the authors report an early termination of the study because of an increase in adverse events. They also observed greater neurocognitive impairment among older patients receiving extreme hemodilution.     

Evidence for Improved Cerebral Function After Minimally lnvasive Bypass Surgery

Abstract Background: Neurological impairment is a major cause of morbidity after cardiac surgery and may be associated with occurrence of cerebral microemboli generated during cardiopulmonary bypass (CPB). This study evaluates cerebral dysfunction following coronary artery surgery on-pump and off-pump. Methods : Neurological outcome was evaluated in 322 patients with a coronary artery bypass graft (CABG). Conventional CPB was used (on-pump) in 305 patients and in 17 patients no CPB was used (off-pump). Intraoperatively, a pulsed-wave transcranial Doppler with a 2-MHZ probe measured high-intensity transient signals (HITS) by ultrasonic insonnation of the middle cerebral artery indicating the presence of emboli within the vessel lumen. Transcranial near-infrared spectroscopy measured cerebral venous oxygen saturation for adequate perfusion. Postoperatively, all patients were subjected to the antisaccadic eye movement (ASEM) test, a sensitive indicator of neurocognitive deficits secondary to frontal lobe dysfunction. Results : While there was no significant difference in O₂ saturation, the number of microemboli HITS generated was significantly higher in the on-pump group than the off-pump group. In the off-pump group, 16 (94%) of 17 patients had perfect scores on the ASEM test, while only 108 (35.4%) of 305 patients achieved a perfect score in the on-pump group (p < 0.01). Furthermore, while all patients in the off-pump group achieved at least 90%, 28% (86/305) in the on-pump group scored "zero" on the ASEM test. Conclusion : Cerebral dysfunction as evidenced by ASEM errors is common following coronary bypass on-pump, but rare with off-pump bypass surgery. Cerebral microemboli generated during CPB may account for this difference. ( J Card Surg 1998;13:27–31     

Effects of Extreme Hemodilution during Cardiac Surgery on Cognitive Function in the Elderly

Background: Strategies for neuroprotection including hypothermia and hemodilution have been routinely practiced since the inception of cardiopulmonary bypass. Yet postoperative neurocognitive deficits that diminish the quality of life of cardiac surgery patients are frequent. Because there is uncertainty regarding the impact of hemodilution on perioperative organ function, the authors hypothesized that extreme hemodilution during cardiac surgery would increase the frequency and severity of postoperative neurocognitive deficits.

Methods: Patients undergoing coronary artery bypass grafting surgery were randomly assigned to either moderate hemodilution (hematocrit on cardiopulmonary bypass >=27%) or profound hemodilution (hematocrit on cardiopulmonary bypass of 15-18%). Cognitive function was measured preoperatively and 6 weeks postoperatively. The effect of hemodilution on postoperative cognition was tested using multivariable modeling accounting for age, years of education, and baseline levels of cognition.

Results: After randomization of 108 patients, the trial was terminated by the Data Safety and Monitoring Board due to the significant occurrence of adverse events, which primarily involved pulmonary complications in the moderate hemodilution group. Multivariable analysis revealed an interaction between hemodilution and age wherein older patients in the profound hemodilution group experienced greater neurocognitive decline (P = 0.03).     

Preoperative statin therapy does not reduce cognitive dysfunction after cardiopulmonary bypass

OBJECTIVE: The purpose of this study was to determine if patients receiving statin therapy before coronary artery bypass grafting surgery would have less cognitive dysfunction after cardiopulmonary bypass as a consequence of a diminished inflammatory response. DESIGN: Retrospective observational study of patients undergoing coronary artery bypass grafting surgery. SETTING: Referral center for cardiothoracic surgery at a university hospital. PARTICIPANTS: Four hundred forty patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Thirty-five percent of patients received statins in the preoperative period. Multivariable analysis revealed no effect of preoperative statin therapy on cognitive function (p = 0.67). Post hoc analysis revealed that statin therapy at hospital discharge was associated with less improvement in cognitive performance at 6 weeks after surgery (p = 0.011). No significant differences were found between statin therapy groups in either range or maximum value of any of the cytokines (p > 0.05). CONCLUSIONS: Preoperative statin therapy did not decrease the inflammatory response to cardiopulmonary bypass or the cognitive dysfunction commonly seen after cardiac surgery.     

Side Effects of Cardiopulmonary Bypass:

Despite many years of clinical and experimental research, the contribution of cardiopulmonary bypass (CPB) and cardioplegic arrest to morbidity and mortality following cardiac surgery remains unclear. This is due, in part, to lack of suitable control group against which bypass and cardioplegic arrest can be compared. The recent success of beating heart coronary artery bypass grafting has, however, for the first time, provided an opportunity to compare the same operation, in similar patient groups, with, or without CPB and cardioplegic arrest. CPB is associated with an acute phase reaction of protease cascades, leucocyte, and platelet activation that result in tissue injury. This is largely manifest as subclinical organ dysfunction that produces a clinical effect in those patients that generate an excessive inflammatory response or in those with limited functional reserve. The contribution of myocardial ischemia/reperfusion, secondary to aortic cross-clamping, and cardioplegic arrest, to the systemic inflammatory response and wider organ dysfunction is unknown, and requires further evaluation in clinical trials.     

Surgical trauma affects the proinflammatory status after cardiac surgery to a higher degree than cardiopulmonary bypass

OBJECTIVES: Cytokines contribute to the development of the systemic inflammatory response syndrome or multiple-organ failure frequently observed after cardiopulmonary bypass-supported cardiac surgery. To quantify the contribution of bypass-induced versus trauma-induced inflammatory response after coronary artery bypass grafting, we examined plasma cytokine levels in 120 patients with coronary artery disease who were treated with or without cardiopulmonary bypass-assisted procedures. METHODS: Patients were treated in accordance with one of the following protocols: (1) elective percutaneous coronary intervention without cardiopulmonary bypass (n = 69), (2) cardiopulmonary bypass-supported percutaneous coronary intervention (cardiopulmonary bypass-percutaneous coronary intervention; n = 10), and (3) cardiopulmonary bypass-supported coronary artery bypass grafting (cardiopulmonary bypass-coronary artery bypass grafting; n = 41). Cytokine levels (picograms/milliliter) were measured by enzyme-linked immunosorbent assay from plasma samples obtained at various time points. RESULTS: Interleukin-6 was measured in blood samples from all 3 patient populations. The maximum interleukin-6 level was 13.6 +/- 22.3 pg/mL in the percutaneous coronary intervention group, 170.4 +/- 165.4 pg/mL in the cardiopulmonary bypass-percutaneous coronary intervention group, and 640.3 +/- 285.7 pg/mL in the cardiopulmonary bypass-coronary artery bypass grafting group. Interleukin-6 levels were significantly different, and the 95% confidence intervals did not overlap. In the cardiopulmonary bypass-percutaneous coronary intervention group, bypass duration correlated well with interleukin-6 production ( r = 0.915; P < .001), whereas these parameters did not correlate in patients who underwent cardiopulmonary bypass-coronary artery bypass grafting ( r = 0.307; P = .054). CONCLUSIONS: These findings support the suggestion that surgical trauma and cardiopulmonary bypass contribute to the inflammatory response after cardiac surgery, although trauma may contribute to a higher degree.     

Beating heart surgery: why expect less central nervous system morbidity?

BACKGROUND: The incidence and etiology of brain dysfunction after conventional coronary artery bypass surgery using cardiopulmonary bypass (CPB) are reviewed. METHODS: Stroke rates and incidences of cognitive dysfunction from various studies are considered. Mechanisms of injury including cerebral embolization as detected by transcranial Doppler and retinal angiography, and imaging-based evidence for postoperative cerebral edema, are discussed. Preliminary results from a prospective clinical trial assessing cognitive dysfunction after beating heart versus conventional coronary artery bypass with CPB are discussed. RESULTS: Initial evidence for lower overall postoperative morbidity, and for a lower incidence of cognitive dysfunction specifically, after nonpump coronary revascularization is presented. CONCLUSIONS: Beating heart surgery results in less potential for generation of cerebral emboli and appears to produce a lower incidence of cognitive dysfunction in both short- and intermediate-term postoperative follow-up periods as compared with conventional coronary artery bypass surgery using CPB.     

On-pump versus off-pump coronary artery bypass grafting: impact on postoperative renal failure requiring renal replacement therapy

BACKGROUND: Despite refinements in perioperative patient management postoperative renal failure requiring hemofiltration or dialysis is still a common complication after coronary artery bypass grafting associated with impaired patient outcome. METHODS: Prospective data on 9,631 patients receiving myocardial revascularization with (coronary artery bypass grafting [n = 8,870]) or without cardiopulmonary bypass (off-pump coronary artery bypass grafting [n = 761]) between April 1996 and August 2001 were evaluated by univariate and multivariate logistic regression analysis. RESULTS: Overall prevalence of postoperative continuous renal replacement therapy was 4.1% (coronary artery bypass grafting, 4.3%; off-pump coronary artery bypass grafting, 1.8%; p = 0.001). Thirty of 40 selected preoperative and intraoperative patient and treatment related variables had a high association with the requirement for postoperative renal replacement therapy; fifteen of these variables were independent predictors in the whole study population. Off-pump coronary artery bypass surgery was identified as having a significantly lower predictive value for postoperative continuous renal placement therapy. In the subgroup of patients undergoing off-pump coronary artery bypass grafting surgery, a second multivariate logistic regression model revealed preoperative cardiogenic shock, urgent operation, intraoperative low cardiac output, and high transfusion requirement as independent predictors for postoperative renal replacement therapy. CONCLUSIONS: Patients with preoperative nondialysis dependent renal insufficiency are at a high risk for further decline in renal function requiring postoperative continuous renal replacement therapy. Off-pump coronary artery bypass surgery is associated with a lower prevalence of postoperative renal replacement therapy after coronary artery bypass grafting.     

The cerebral complications of coronary artery bypass surgery.

A prospective study of 79 coronary artery bypass surgery patients has been undertaken to determine the cerebral consequences of this form of surgery. Thirty comparative major vascular and thoracic non-cardiopulmonary bypass patients have also been studied. Detailed neurological, neuropsychological and cerebral blood flow investigations were undertaken preoperatively and at 8 days and 8 weeks postoperatively. Whilst stroke was rare following coronary artery bypass surgery, only one case in 76 being found (less than 1%), moderate or severe neuropsychological deficit was common, occurring in 49 of 67 patients (73%) 8 days after surgery and in 25 of 67 patients (37%) 8 weeks after surgery. However, the non-cardiopulmonary bypass patients also showed comparative levels of neuropsychological deficit. Cerebral blood flow was significantly reduced 8 days following coronary artery bypass surgery but not at 8 weeks and not in the comparative group. Significant cerebral blood flow reduction 8 days after coronary artery bypass graft surgery was not related to neuropsychological deficit found at a similar time. A greater neuropsychological deficit was found with longer cardiopulmonary bypass times but increased length of cardiopulmonary bypass appeared not to be related to an increased cerebral blood flow reduction.     

体外循环与非体外循环下冠状动脉旁路移植术孰优孰劣

近年来冠状动脉旁路移植术有了很大的进展。采用非体外循环冠状动脉旁路移植术能避免体外循环带来的并发症,而得到越来越多的重视,但其技术难度大;传统的冠状动脉旁路移植术在体外循环的辅助下可以提供较好的血管吻合条件,仍被广泛采用。现将对两种手术方法的移植血管通畅率、死亡率、炎症反应、凝血与抗凝的影响、器官系统损伤、住院时间和费用、术式转换等方面的比较进行综述。     

Port-access minimally invasive cardiac surgery increases surgical complexity, increases operating room time, and facilitates early postoperative hospital discharge

BACKGROUND: Proposed advantages of port-access cardiac surgery have yet to be substantiated. The authors retrospectively compared patients undergoing port-access cardiac surgery with a matched group undergoing conventional cardiac surgery. METHODS: Forty-six patients who underwent port-access cardiac surgery were matched with 46 who underwent conventional cardiac surgery. Absolute criteria for matching included morning-of-surgery admission, procedure undergone, and care being delivered by one of two surgeons. If possible, matching included care delivered by one of two anesthesiologists. Patients were matched as closely as possible for preoperative demographic and clinical characteristics. RESULTS: All 46 pairs of patients were matched for procedure and admitted the morning of surgery. All 92 operations were performed by one of two surgeons, and 89% were performed by one of two anesthesiologists. Preoperative demographic and clinical characteristics were equivalent between groups. Compared with conventional cardiac surgery, port-access cardiac surgery increased surgical complexity (it almost tripled cardiopulmonary bypass time during coronary artery bypass grafting and increased it almost 40% during mitral valve procedures) and increased total operating room time (P < 0.0001). Port-access cardiac surgery had no beneficial effect on earlier postoperative extubation, decreased incidence of atrial fibrillation, or intensive care unit time, yet it decreased postoperative duration of stay (P = 0.029, all patients), a benefit observed primarily in patients undergoing coronary artery bypass grafting (P = 0.002). CONCLUSIONS: This retrospective analysis revealed that port-access cardiac surgery increases surgical complexity, increases operating room time, has no effect on earlier postoperative extubation or decreased incidence of atrial fibrillation or intensive care unit time, and may facilitate postoperative hospital discharge (primarily in patients undergoing coronary artery bypass grafting). Properly designed prospective investigation is necessary to ascertain whether port-access cardiac surgery truly offers any benefits over conventional cardiac surgery.     

Staged coronary artery bypass grafting after percutaneous angioplasty for intracranial vascular stenosis

OBJECTIVE: Cerebrovascular disease is commonly associated with coronary artery disease and is a major risk factor for cardiac surgery. Concomitant coronary artery bypass grafting and carotid endarterectomy may reduce the risk of stroke; however, this staged operation is effective only for extracranial lesions. The strategy for on-pump coronary artery bypass grafting for patients with intracranial vascular stenosis is still controversial. METHODS: The subjects were 157 consecutive candidates for coronary artery bypass grafting who underwent computed tomography and digital subtraction cerebral angiography preoperatively to check for cerebrovascular disease. Additional single-photon emission computed tomography was performed to evaluate cerebral ischemia, according to the neurologist's request. Patients with diffuse intracranial vascular stenosis impossible to treat with percutaneous transluminal angioplasty underwent off-pump coronary artery bypass grafting. Patients with a circumflex coronary artery lesion first underwent percutaneous transluminal angioplasty for cerebral vascular stenosis followed by secondary on-pump coronary artery bypass grafting. RESULTS: Three patients were selected for staged operations. Percutaneous transluminal angioplasty was performed for 4 intracranial stenotic lesions. All lesions were dilated successfully, and no complications developed during or after the procedure. All patients tolerated staged coronary artery bypass grafting and were extubated within 1 day without any mental disturbance. No further neurologic complication occurred, and computed tomography performed postoperatively revealed no significant changes. CONCLUSION: Staged on-pump coronary bypass after percutaneous transluminal angioplasty for cerebrovascular disease may reduce the risk of stroke during cardiopulmonary bypass, and it is useful especially in patients with intracranial cerebrovascular disease.     

Bacterial translocation secondary to small intestinal mucosal ischemia during cardiopulmonary bypass. Measurement by diamine oxidase and peptidoglycan.

OBJECTIVES: To demonstrate that small intestinal mucosal ischemia occurs during cardiopulmonary bypass by measuring serum diamine oxidase activity, an index of small intestinal mucosal ischemia, in perioerative patients undergoing cardiovascular surgery with and without cardiopulmonary bypass. METHODS: Twelve successive patients who underwent coronary artery bypass grafting with cardiopulmonary bypass (Group I) were compared to 10 patients who underwent off-pump coronary artery bypass grafting (Group II). Serum diamine oxidase activity, blood lactate concentration, and serum peptidoglycan concentration were measured perioperatively. RESULTS: Serum diamine oxidase activity rose after the start of cardiopulmonary bypass and continued to rise throughout cardiopulmonary bypass in Group I, while activity was unchanged in Group II. The serum lactate concentration mirrored the change in the diamine oxidase activity in both groups. The peptidoglycan concentration in Group I rose after the start of cardiopulmonary bypass and returned to near normal concentrations after surgery. CONCLUSIONS: The parallel rise in diamine oxidase activity and the serum lactate concentration in Group I implies that ischemic injury to the mucosa of the small intestine occurs during cardiopulmonary bypass, and the rise in the serum peptidoglycan concentration indicates that bacteremia did occur. Thus, cardiopulmonary bypass causes hypoperfusion of small intestinal mucosa and consequently bacterial translocation.     

Clinical and Angiographic Outcome of Coronary Surgery with and without Cardiopulmonary Bypass: A Prospective Randomized Trial

Abstract Background: Off-pump coronary artery bypass surgery has emerged as an alternative technique to traditional onpump surgery. The aim of this randomized study was to compare perioperative morbidity and mortality and intraoperative and short-term graft patency in off-pump and on-pump coronary artery bypass grafting. Methods: One hundred twenty patients were randomized for coronary revascularization with or without cardiopulmonary bypass. In all patients grafts and anastomoses were monitored with transit time Doppler ultrasonography and angiography. Angiography was repeated 3 months after the procedure in 115 of the patients. Results: Angiography 3 months postoperatively revealed that internal mammary artery patency was 98% in both groups. Vein graft patency was 83% in the off-pump group and 91% in the on-pump group, a difference that was not statistically significant. One perioperative death was recorded in each group. Two strokes were recorded in the on-pump group, none in the off-pump group. Conclusion: In this prospective, controlled study, perioperative and short-term outcome of off-pump coronary surgery equaled that of on-pump surgery.     

Development and clinical application of minimally invasive cardiac surgery using percutaneous cardiopulmonary support.

OBJECTIVES: Optimal cardiopulmonary support during minimally invasive cardiac surgery remains controversial. We developed cardiopulmonary bypass for minimally invasive cardiac surgery using percutaneous peripheral cannulation. METHODS: Subjects were 34 patients (age: 58 +/- 13 years; range: 17-73) undergoing minimally invasive cardiac surgery using percutaneous cardiopulmonary support between June 1997 and March 1999. Procedures included atrial septal defect closure (n = 14), partial atrioventricular septal defect closure (n = 1), mitral valve replacement (n = 8), mitral valve repair (n = 3), aortic valve replacement (n = 6), coronary artery bypass grafting (n = 1), and right atrial myxoma extirpation (n = 1). Bicaval venous drainage from the right internal jugular vein and the femoral vein and arterial return to the femoral artery were instituted by percutaneous cannulation. Venous drainage was implemented by negative pressure (-20 to -40 mmHg) and arterial return was by conventional roller pump. All procedures were conducted through a skin incision 8 +/- 1 cm, from 6 to 10 cm and partial sternotomy. Aortic cross clamping and cardioplegic solution were administered in the surgical field. RESULTS: The operation lasted 224 +/- 45 min., cardiopulmonary bypass 104 +/- 32 min., and aortic clamping 77 +/- 23 min.. No deaths occurred. One patient with residual atrial septal defect required reoperation through the same skin incision. Only 1 patient required homologous blood transfusion. The average postoperative hospital stay was 15 +/- 5 days. CONCLUSIONS: Minimally invasive cardiac surgery using percutaneous cardiopulmonary support is safe and an excellent option for selected patients affected by single valve lesion, simple cardiac anomalies, and coronary artery bypass grafting.     

Erweitertes zerebrales Monitoring mit transkranieller Doppler-Sonographie und zerebrovenöser Oxymetrie während einer Reanimation

This case report describes cerebral monitoring of intracranial haemodynamics using transcranial Doppler sonography (TCD) and jugular bulb oxygen saturation (SjO₂) by fiberoptic jugular bulb oximetry during cardiac arrest following cardiac surgery involving cardiopulmonary bypass (CPB). CPB for aortic valve replacement and coronary artery bypass grafting was performed in a 63-year-old patient previously operated upon for heart disease. Mean blood flow velocity was measured in the middle cerebral artery using a bidirectional 2?MHz TCD system. SjO₂ was measured using a fiberoptic thermodilution catheter placed in the right jugular bulb via the right internal jugular vein under radiographic control. At the end of the operation, low cardiac output syndrome and cardiac arrest occurred, which required reopening of the thorax and cardiopulmonary resuscitation (CPR) until CPB could be resumed. Following extrathoracic cardiac resuscitation, systolic “spikes”, loss of the diastolic flow profile, and no increase in SjO₂ were recorded by the monitors, indicating cerebral circulatory arrest. However, a normal flow profile with increasing diastolic portions and an increase in SjO₂ to 52% were seen following optimisation of the open thorax cardiac resuscitation. This monitoring may be able to give information to optimise therapy during CPR to avoid ischaemic cerebral injury.     

Short-term and long-term cognitive function and cerebral perfusion in off-pump and on-pump coronary artery bypass patients.

OBJECTIVE: The aim of this study was to evaluate cognitive function, as measured by serial neuropsychological testing, and cerebral perfusion, as measured by brain SPECT scanning in patients with coronary artery diseases (CAD) following off-pump and on-pump coronary artery bypass graft surgery. Besides, the relationship between cerebral blood flow, cognitive functions, surgery parameters, and cardiac function in these patients were estimated. Also, brain-protective effects of instenon were studied. METHODS: Brain SPECT and comprehensive neuropsychological testing were performed 1 day before, 10-14 days and 6 months after coronary artery bypass graft surgery (CABG). The study involved 65 patients (62 males and 3 females, mean age 55+/-2) who underwent CABG with cardiopulmonary bypass (CPB) (43 pts) and off-pump coronary revascularization (OPCAB) using the Octopus stabilization system (22 pts). In 21 cases employing CPB, for prevention of the impairments of cerebral perfusion and cognitive deficit instenon was administered. RESULTS: CABG with the use of extracorporeal circulation is complicated by short-term and long-term neurocognitive dysfunction (in 96 and 55% cases, correspondingly). Also, in the early period after CABG, in 68% patients, decrease in regional cerebral blood flow (rCBF) was found, and after 6 months brain perfusion was lower than the baseline in 55% cases. Relationship between postoperative rCBF changes and the dynamics of cognitive function was found in early period and after 6 months following CABG. CONCLUSION: The coronary revascularization on beating heart or preventive administration of instenon in CPB patients helps significantly to diminish the risk of cerebrovascular complication.