Cognitive brain function after hypothermic circulatory arrest assessed by cognitive P300 evoked potentials.

BACKGROUND: The role of hypothermic circulatory arrest (HCA) in cardiovascular surgery is controversial and assumed to result in neurocognitive dysfunction that is not always detected by standard clinical observation. We assessed cognitive P300 visual evoked potentials (P300) in patients undergoing either HCA or coronary artery bypass grafting (CABG) to elucidate whether HCA was associated with postoperative cognitive decline. METHODS: Thirteen patients undergoing either aortic arch replacement (n=4) or pulmonary thromboendarterectomy (n=9) using HCA (mean: 28+/-11 min, 22+/-2 degrees C) were studied. They were compared to 13 patients undergoing on-pump CABG. P300s were measured 1 day before and 1 week after the operation. We assessed an area under the curve (AUC) between 280 and 600 ms and center of this area [Ct (time), Cv (voltage)]. The ratio of these parameters acquired by target (TG) and non-target (NTG) stimulus (TG/NTG) was calculated to assess concentration on TG stimulus and defined as concentration index (CI: CI(AUC), CI(Ct), and CI(Cv)). RESULTS: There was no significant difference in preoperative characteristics between groups. There were neither strokes nor hospital deaths. Preoperatively, the HCA group could not concentrate on target stimulus as well as the control group in frontal leads (CI(AUC) and CI(Cv) were lower in HCA group than in control group). However, the HCA group could concentrate on target stimulus better than the control group postoperatively because postoperative CI(AUC) (pre-operation: 1.1+/-0.5 to post-operation: 1.7+/-0.4, P=.02) and CI(Cv) (1.1+/-0.4 to 1.6+/-0.4, P=.01) were significantly improved in the HCA group, whereas these were significantly impaired in the control group (CI(AUC): 1.6+/-0.6 to 1.3+/-0.4, P=.03, CI(Cv): 1.5+/-0.5 to 1.2+/-0.3, P<.01). Postoperative CI(Ct) in the HCA group were significantly impaired in all leads. The duration of HCA did not correlate with any values of postoperative P300. No specific trends were observed in either preoperative or postoperative P300 values between patients with or without postoperative temporary neurological dysfunction (one in each group). Postoperative improvement of CI(AUC) and CI(Cv) in Fz lead were found in 85 and 69% in the HCA group and 23 and 23% in the control group, respectively (CI(AUC): P<.01, CI(Cv): P<.05). CONCLUSIONS: P300 detected no significant neurocognitive impairment due to the relatively brief period of HCA (approximately 28 min).

CT scan findings in chronic thromboembolic pulmonary hypertension: predictors of hemodynamic improvement after pulmonary thromboendarterectomy.

STUDY OBJECTIVES: The aim was to correlate CT scan findings with hemodynamic measurements in patients who had undergone pulmonary thromboendarterectomy (PTE) and to evaluate whether CT scan findings can help to predict surgical outcome. PATIENTS AND METHOD: Sixty patients who underwent PTE and preoperative helical CT scanning were included. Preoperative and postoperative hemodynamics were correlated with preoperative CT imaging features. RESULTS: The diameter of the main pulmonary artery (PA) and the ratio of the PA and the diameter of the ascending aorta correlated with preoperative mean pulmonary artery pressure (PAP) [r = 0.42; p < 0.001; and r = 0.48; p < 0.0001, respectively]. There was a significant correlation of subpleural densities with preoperative pulmonary vascular resistance (PVR) [r = 0.44; p < 0.001] and of the number of abnormal perfused lobes with preoperative PAP (r = 0.66; p < 0.0001) and PVR (r = 0.76; p < 0.0001). Postoperative PVR correlated negatively with the presence and extent of central thrombi (r = -0.36; p = 0.007) and dilated bronchial arteries (p = 0.03) seen on preoperative CT scans. Sixty percent of patients (3 of 5 patients) without visible central thromboembolic material on CT scans had an inadequate hemodynamic improvement in contrast to 4% of patients (2 of 51 patients) with central thrombi (p = 0.003). Preoperative PVR (r = 0.31; p = 0.018) and the extent of abnormal lung perfusion (r = 0.37; p = 0.007) and of subpleural densities (r = 0.32; p = 0.017) were positively correlated with postoperative PVR. CONCLUSIONS: In patients with thromboembolic pulmonary hypertension, CT scan findings can help to predict hemodynamic improvement after PTE. The absence of central thrombi is a significant risk factor for inadequate hemodynamic improvement.

[CT findings in patients with chronic thrombembolic pulmonary hypertension]. / SpiralCcT bei chronisch thrombembolischer pulmonaler Hypertonie.

Chronic thromboembolic pulmonary hypertension (CTEPH) is thought to be a rare complication of pulmonary embolism. However, it was recently demonstrated that CTEPH is more common than previously thought after pulmonary embolism. Without treatment, CTEPH is associated with a very high mortality rate. Making the correct diagnosis early is essential, because there is a potential curative treatment in the form of pulmonary thromboendarterectomy (PTE). Because of the unspecific clinical symptoms of CTEPH, the different imaging modalities play a crucial role in diagnosis making. Since the introduction of the multidetector CT technology, CT has become an important part in the diagnostic work up of pulmonary embolism and CTEPH and is often used as a first-line diagnostic tool. CT is not only a reliable tool for the diagnosis of CTEPH, but also is helpful in estimating the operability of these patients. PTE is still associated with a mortality rate of about 10%. Particularly an insufficient decrease of the pulmonary vascular resistance after PTE leads to a very high mortality rate. Therefore, it is crucial to correlate the degree of the surgical accessible obstruction of the pulmonary vasculature with the degree of pulmonary hypertension in deciding for or against PTE. The aim of this review is to describe the CT findings in patients with CTEPH and their use in differentiating CTEPH from other diseases like acute pulmonary embolism and primary pulmonary hypertension. Moreover, the correlation of different CT imaging features with surgical success after PTE will be discussed.

Cytokine response to pulmonary thromboendarterectomy.

BACKGROUND: Pulmonary thromboendarterectomy (PTE) is an effective but challenging treatment for chronic thromboembolic pulmonary hypertension (CTEPH). PTE is associated with marked hemodynamic instability in the perioperative course, suggesting the involvement of circulating mediators. The aim of this study was to characterize the expression of proinflammatory and anti-inflammatory cytokines in patients undergoing PTE. METHODS: Fourteen patients with CTEPH (mean [+/- SD] pulmonary vascular resistance, 1,056 +/- 399 dyne.s.cm(-5)) underwent PTE using cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA). Peripheral arterial blood samples were drawn prior to patients undergoing sternotomy, during CPB, before and after DHCA, and 0, 8, 16, 24, and 48 h after surgery. An enzyme-linked-immunosorbent assay was used to analyze the plasma levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-10. Seven patients undergoing aortic arch replacement (ARCH) in DHCA served as a control group. RESULTS: Prior to and during PTE, the CTEPH patients exhibited elevated TNF-alpha levels, which decreased within the first 24 postoperative hours (p = 0.02). There was no TNF-alpha release among patients in the ARCH group. IL-6 levels were similar in both groups throughout the perioperative course. A profound anti-inflammatory response was observed in the PTE group, which was reflected by elevated IL-10 levels prior to surgery and a marked peak level immediately after surgery. A positive correlation was found between maximum vasopressor support and peak levels of IL-6 (r = 0.82) in the PTE patients. CONCLUSION: Heart failure due to CTEPH appears to generate a pronounced inflammatory response with the release of proinflammatory and anti-inflammatory cytokines. PTE results in the rapid normalization of preoperatively elevated TNF-alpha levels. IL-6-mediated systemic inflammatory cascades may be involved in the regulation of peripheral vascular tone after PTE.

Predictors of postoperative outcome after pulmonary endarterectomy from a 14-year experience with 279 patients.

OBJECTIVE: Postoperative outcome after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) is difficult to predict. We sought to analyze specific preoperative findings to predict mortality, shorter mechanical ventilation, and hemodynamic improvement after PEA. METHODS: A total of 279 patients with CTEPH (57 ± 14 years old, 57% male), who underwent PEA between 1995 and 2009, were reviewed retrospectively. Preoperative pulmonary hemodynamic parameters, spirometry data, laboratory data, cardiac co-morbidities, clinical stage, and number of desobliterated segments were analyzed using a logistic regression model to identify independent predictors for early mortality, shorter duration of mechanical ventilation, and hemodynamic improvement. RESULTS: There were 31 early deaths (11.1%, last three years: 6.7%). Among 16 significant predictors for early mortality, preoperative arterial oxygenation was the only significant predictor in multivariate analysis (P < 0.05). A total of 147 patients (52.7%) could be extubated within 48 h postoperatively. Out of 16 significant predictors in univariate analysis for mechanical ventilation less than 48 h, only higher forced expiratory volume in 1s FEV1.0 (P < 0.05) and higher preoperative cardiac index (P < 0.05) were significant in multivariate analysis. In 185 patients (66.3%), postoperative pulmonary vascular resistance (PVR) was reduced to lower than 400 dyn s(-1) cm(-5) at 48 h after PEA. Male gender (P < 0.05), lower preoperative mean pulmonary arterial pressure (PAP) (P < 0.05), and more intra-operative desobliterated segments (P < 0.01) were identified as significant predictors for this hemodynamic response with sensitivity of 77.5% and specificity of 67.9%. Using Pearson's correlation coefficient, PVR at 48 h after PEA could be estimated as PVR = 123.266+135.471 × creatinine-22.053 × desobliterated segments + 3.248 × systolic PAP (P < 0.01, R(2) = 0.401, 95% confidence interval = 0.464-0.830). CONCLUSIONS: Preoperative factors can primarily predict postoperative outcome after PEA. Patients with underlying parenchymal lung disease will have increased risk for early mortality and prolonged mechanical ventilation. The extent of desobliterated segments as well as preoperative hemodynamic severity play a key role in predicting good hemodynamic responders.

Angiographic predictors of hemodynamic improvement after pulmonary endarterectomy.

BACKGROUND: Postoperative outcome after pulmonary endarterectomy (PEA) for CTEPH (chronic thromboembolic pulmonary hypertension) is difficult to predict. We analyzed specific angiographic findings to predict the success of PEA. METHODS: Pulmonary angiograms were reviewed retrospectively in 90 patients with CTEPH who underwent PEA. The proximal 2 cm of a segmental artery were classified into the following: A, occlusion; B, pouch or membrane; or C, delayed perfusion. The number of involved segments was recorded. Logistic regression analysis was used to predict mortality and hemodynamic improvement after PEA. RESULTS: An average of 15.7 +/- 2.9 segments were involved angiographically per patient (A, 7.6 +/- 2.9; B, 4.6 +/- 3.1; C, 3.5 +/- 2.7). No variable was significant in multivariate analysis to predict early mortality (n = 6, 6.7%). More than 50% reduction in postoperative pulmonary vascular resistance (PVR) at 24 hours (n = 71) could be predicted by higher PVR, more involved segments, male gender, and higher diastolic pulmonary arterial pressure with an area under the curve in the receiver operating characteristics curve of 0.9021. The PVR less than 400 dynes x sec x cm(-5) at 48 hours after PEA (n = 81) could be predicted by type B lesions, duration of symptoms, more involved segments, and serum creatinine level with area under the curve in the receiver operating characteristics curve of 0.9160. The PVR at 48 hours after PEA could be predicted by serum creatinine level, involved segments, PVR, and gender (P < 0.001, R = 0.551, R(2) = 0.304). CONCLUSIONS: Angiographic criteria can predict the success of PEA. Segments with obstruction but preserved peripheral perfusion seem to have more impact than occluded segments on hemodynamic improvement.

Managing pulmonary artery catheter-induced pulmonary hemorrhage by bronchial occlusion.

A 76-year-old woman underwent mitral valve repair and coronary artery bypass grafting. Intrabronchial bleeding occurred after inflation of the balloon tip of the pulmonary artery catheter in the wedge position. A Forgaty catheter was introduced into the trachea parallel to the endotracheal tube and advanced under bronchoscopic vision into the intermediate bronchus. Tamponade of the bleeding was achieved by by filling the Forgaty balloon tip with saline. Weaning from extracorporeal circulation was uneventful. On the first postoperative day, the Forgaty catheter was removed and bronchial lavage of the middle and lower lobe was performed without any additional bleeding complication.

Cusp repair in aortic valve reconstruction: does the technique affect stability?

OBJECTIVE: Cusp prolapse may be an isolated cause of aortic regurgitation or may exist in conjunction with dilatation of the proximal aorta. Prolapse can be corrected by central plication, triangular resection, or pericardial patch implantation. We retrospectively analyzed our results with these techniques. METHODS: From October 1995 to December 2006, 604 patients (aged 3-86 years) underwent aortic valve repair. Cusp prolapse was found in 427 patients (246 tricuspid, 181 bicuspid). Prolapse was corrected by central plication (n = 275) or triangular resection (n = 80). A pericardial patch was implanted for pre-existing cusp defects or after excision of calcium (n = 72). One cusp was repaired in 198 patients; the remaining patients underwent repair of 2 (n = 189) or 3 cusps (n = 40). In 102 patients more than one technique was used, and the patients were allocated to the group of the assumedly more complex repair (central plication < triangular resection < pericardial patch plasty). Cumulative follow-up was 1238 patient-years (mean 35 +/- 27 months). RESULTS: Hospital mortality was 2.6% (11/427). Actuarial freedom from aortic regurgitation of grade II or more at 5 years was 92% (central plication), 90% (triangular resection), and 90% (pericardial patch plasty). Thirteen patients were reoperated on, with prolapse as the most common reason for failure (n = 7); 6 underwent re-repair. Freedom from reoperation at 5 years was 95% (central plication), 94% (triangular resection), and 94% (pericardial patch plasty). Freedom from valve replacement at 5 years was 97% (central plication), 99% (triangular resection), and 98% (pericardial patch plasty). CONCLUSIONS: In aortic valve repair, cusp prolapse can be treated reliably by central plication. In the presence of more complex disease, triangular resection or pericardial patch plasty may be used without compromising midterm durability.

Bronchovascular versus bronchial sleeve resection for central lung tumors.

BACKGROUND: Pneumonectomy has traditionally been the treatment of choice for central lung tumors. Bronchial sleeve resections are increasingly considered as a reasonable alternative. For tumor involvement of both central airways and pulmonary artery, bronchovascular sleeve resections are possible, but considered to be technically demanding and associated with a higher perioperative risk. In addition, their role as adequate oncologic treatment for lung cancer is unclear. We have compared the early and long-term results of bronchovascular sleeve resection with those of bronchial sleeve resection and pneumonectomy. METHODS: We retrospectively analyzed all patients who underwent bronchial sleeve resection (group I, n = 104), bronchovascular sleeve resection (group II, n = 67), and pneumonectomy (group III, n = 63) for central lung cancer in our institution. RESULTS: The groups were comparable regarding demographics and tumor, node, and metastasis (TNM) stage. Early mortality was 1.9% in group I, 1.5% in group II, and 6.3% in group III (p = 0.19). The rate of bronchial complications was 0.96% in group I, 0% in group II, and 7.9% in group III (p = 0.006). Five-year survival was 46.1% in group I, 42.9% in group II, and 30.4% in group III (p = 0.16). Freedom from local recurrence of disease (5 years) was 83.8% in group I, 84.2% in group II, and 88.7% in group III (p = 0.56). CONCLUSIONS: Bronchovascular sleeve resections are as safe as bronchial sleeve resections for the treatment of central lung cancer. Both procedures have comparable early and long-term results, which are similar to those of pneumonectomy. It appears reasonable to apply bronchovascular sleeve resections more liberally.

Circulating big endothelin-1: an active role in pulmonary thromboendarterectomy?

BACKGROUND: Pulmonary thromboendarterectomy is an effective treatment for patients with chronic thromboembolic pulmonary hypertension. The early postoperative course may be associated with pulmonary vasoconstriction and profound systemic vasodilation. We investigated the potential involvement of endothelins in these hemodynamic alterations. METHODS: Seventeen patients with chronic thromboembolic pulmonary hypertension (pulmonary vascular resistance, 1015 +/- 402 dyne x s x cm(-5) [mean +/- SD]) underwent pulmonary thromboendarterectomy with cardiopulmonary bypass and deep hypothermic circulatory arrest. Peripheral arterial blood samples were drawn before sternotomy, during cardiopulmonary bypass before and after deep hypothermic circulatory arrest, and 0, 8, 16, and 24 hours after surgery and were analyzed for big endothelin-1. The patients were divided into 2 groups according to whether their preoperative big endothelin-1 plasma level was above or below the cutoff point of 2.1 pg/mL, as determined by receiver operating characteristic curve analysis (group A, big endothelin-1 <2.1 pg/mL, n = 8; group B, big endothelin-1 > or =2.1 pg/mL, n = 9). RESULTS: Patients in group B, with higher preoperative big endothelin-1 levels (3.2 +/- 1.0 pg/mL vs 1.5 +/- 0.4 pg/mL; P < .001), were poorer operative candidates (preoperative mean pulmonary artery pressure, 51.3 +/- 7.1 mm Hg vs 43.6 +/- 6.2 mm Hg; P = .006) and had a poorer outcome (mean pulmonary artery pressure 24 hours after surgery, 32.6 +/- 9.5 mm Hg vs 21.8 +/- 6.2 mm Hg; P < .001). Positive correlations were found between preoperative big endothelin-1 levels and preoperative mean pulmonary artery pressure (r = 0.56; P = .02) as well as postoperative mean pulmonary artery pressure at 0 hours (r = 0.70; P = .002) and 24 hours (r = 0.63; P = .006) after surgery. Preoperative big endothelin-1 levels predicted outcome (postoperative mean pulmonary artery pressure at 24 hours after surgery) after pulmonary thromboendarterectomy (area under the receiver operating characteristic curve, 0.85). Peak big endothelin-1 levels also correlated with maximal vasopressor dosage (r = 0.65; P = .004). CONCLUSIONS: Preoperative big endothelin-1 levels seem to correlate with the hemodynamic alterations observed in pulmonary thromboendarterectomy and may be used to predict hemodynamic outcome after pulmonary thromboendarterectomy.

Clinical value of routine predischarge testing after ICD-implantation.

AIMS: After implantation of a cardioverter/defibrillator (ICD) predischarge testing is often performed to ensure appropriate therapy function. Nevertheless there is no proven evidence for the necessity of this examination. In this retrospective single-centre analysis we investigated the clinical value of routine predischarge testing. METHODS AND RESULTS: Predischarge testing was performed in 161 patients 6+/-2 days after primary implantation of an ICD. There were no complications related to ICD-testing. In 17 of 161 patients (11%) there was at least one pathological finding. In 4 of 17 patients we observed a defibrillation energy requirement (DER) with a safety margin of less than 10J. In two of these patients an early lead repositioning was undertaken and in two patients reversal of the shock polarity was used to achieve an adequate DER. In 13 of 17 patients we detected a distinct deviation of pacing thresholds or R-wave sensing amplitudes. In two of these patients an early electrode repositioning was performed because of lead displacement. In the remaining 11 patients we found an adequate DER at first, whereas in two patients a further lead repositioning was still necessary during follow-up. In 144 of 161 patients (89%) predischarge testing was without pathological findings. None of these patients needed revision of the ICD-lead during a mean follow-up of 24+/-13 months. CONCLUSIONS: Abnormal measurements during predischarge testing are not rare findings in ICD-recipients. Noninvasive methods cannot rule out inadequate defibrillation function. A normal predischarge test seems to be a reliable predictor for a stable electrode function during the first years of follow-up.