The Effect of Hemodynamic Parameters on Cerebral Oxygenization During Carotid Endarterectomy

Abstract Objective/Introduction: Near-infrared spectroscopy (NIRS) is a non-invasive technique to detect cerebral ischemia by monitoring changes in regional cerebral oxygenation (rSO2) in the frontal lobes. However, there are no studies showing the changes in NIRS values in response to hemodynamic variations during stages of carotid endarterectomy (CEA) procedure and clinical implications of these changes. The aim of this study was to determine if hemodynamic changes affect NIRS values during carotid endarterectomy and if our results may help to provide strategies for hemodynamic management in these patients. Methods: A total of 50 consecutive patients undergoing CEA were prospectively included in the study. NIRS was measured at first minute after clamping of carotid artery, and then systolic blood pressure was increased above 150 mmHg. NIRS values from both hemispheres were recorded simultaneously at certain time points and were analyzed to evaluate the changes at different stages of operation and to assess correlations with hemodynamic parameters. Results: NIRS values on the right and left sides were correlated with systolic (right P<0.001, R2:0.24; left P=0.02, R2:0.10) diastolic (right P<0.001, R2:0.36; left P=0.001, R2:0.18) and mean (right P<0.001, R2:0.33; left P=0.003, R2:0.17) blood pressures when the patient was under general anaesthesia. NIRS values were significantly lower than pre-incision values just after clamping of carotid artery in both hemispheres (P=0.005 for the right and P<0.001 for the left side). Conclusion: NIRS values measured in our study show that there is a correlation between hemodynamic changes and cerebral oxygenation. This effect is especially pronounced while the patient is asleep and intubated, which implies the importance of close monitoring of patients with carotid disease during any surgery requiring general anaesthesia.

The role of immature platelet count and immature platelet fraction in determining the need for transfusion in patients undergoing CABG.

BACKGROUND: Platelet dysfunction has been shown to play a role in postoperative bleeding, however it is not clear whether immature platelets (IP) can induce appropriate homeostasis to prevent excessive bleeding in patients undergoing coronary artery bypass grafting (CABG). The aim of this study was to evaluate the postoperative change in IP count (IPC), IP fraction (IPF) and mean platelet volume (MPV), and to examine their relationship with postoperative bleeding and blood transfusion. METHODS: One hundred and forty-nine consecutive patients undergoing elective CABG were included in this prospective study. All CABGs were performed by the same surgical team in a standardised method, utilising the on-pump technique. IPC, MPV and IPF were measured pre-operatively, after the completion of surgery, and at the postoperative first, third and fifth days. The primary outcome measure of this study was whether the need for transfusion was associated with IP, IPF, MPV and platelet count. RESULTS: There was a significant decrease of 7.77% in IPC on the day of the operation. Pre-operative IPC and IPF were correlated with postoperative drainage (p < 0.001), intraoperative blood transfusion (p < 0.001) and intensive care unit blood transfusion (p < 0.001). Pre-operative haemoglobin levels were significantly correlated with length of hospital stay. However, neither pre-operative IPC nor IPF were associated with length of hospital stay. Postoperative IPC was however associated with the length of hospital and intensive care unit stay (p = 0.008 and p = 0.009, respectively). CONCLUSIONS: Pre-operative IPC and IPF were significantly correlated with postoperative drainage and blood transfusion frequency. In patients undergoing CABG, these can be seen as serious guiding parameters in the estimation of postoperative bleeding.

The Effect of Hemodynamic Parameters on Cerebral Oxygenization During Carotid Endarterectomy.

OBJECTIVE/INTRODUCTION: Near-infrared spectroscopy (NIRS) is a non-invasive technique to detect cerebral ischemia by monitoring changes in regional cerebral oxygenation (rSO2) in the frontal lobes. However, there are no studies showing the changes in NIRS values in response to hemodynamic variations during stages of carotid endarterectomy (CEA) procedure and clinical implications of these changes. The aim of this study was to determine if hemodynamic changes affect NIRS values during carotid endarterectomy and if our results may help to provide strategies for hemodynamic management in these patients. METHODS: A total of 50 consecutive patients undergoing CEA were prospectively included in the study. NIRS was measured at first minute after clamping of carotid artery, and then systolic blood pressure was increased above 150 mmHg. NIRS values from both hemispheres were recorded simultaneously at certain time points and were analyzed to evaluate the changes at different stages of operation and to assess correlations with hemodynamic parameters. RESULTS: NIRS values on the right and left sides were correlated with systolic (right P<0.001, R2:0.24; left P=0.02, R2:0.10) diastolic (right P<0.001, R2:0.36; left P=0.001, R2:0.18) and mean (right P<0.001, R2:0.33; left P=0.003, R2:0.17) blood pressures when the patient was under general anaesthesia. NIRS values were significantly lower than pre-incision values just after clamping of carotid artery in both hemispheres (P=0.005 for the right and P<0.001 for the left side). CONCLUSION: NIRS values measured in our study show that there is a correlation between hemodynamic changes and cerebral oxygenation. This effect is especially pronounced while the patient is asleep and intubated, which implies the importance of close monitoring of patients with carotid disease during any surgery requiring general anaesthesia.

Is Biochemical Follow Up Possible in Peripheral Arterial Disease Treatment: Hypoxia Inducible Factor-1 Alpha?

PURPOSE: The hypoxia inducible factor (HIF)-1 is a dimeric protein complex that plays an integral role in the body's response to hypoxia. This study aimed to analyze the regulation of HIF-1α following vascular and/or endovascular surgery in peripheral arterial disease (PAD) patients. MATERIALS AND METHODS: A total of 40 patients with PAD (≥Rutherford category 3) were included in this prospective study. The mean age was 61.9±9.2 years. Open surgery was performed in 16 patients, and endovascular intervention was performed in 34 patients. At preoperative (T1), postoperative day 1 (T2), and month 3 (T3), the serum HIF-1α levels were checked using the ELISA technique. RESULTS: At T3, the ankle-brachial index was significantly higher than the preoperative value (P<0.001). Serum HIF-1α levels at T1, T2, and T3 were 2.0±1.7 ng/mL, 1.9±1.7 ng/mL, and 1.6±1.4 ng/mL, respectively. Serum HIF-1α levels between T1 and T3 and between T2 and T3 were significantly different (P<0.05). The preoperative HIF-1α levels were lowest in iliac lesions compared to femoropopliteal or tibial lesions. CONCLUSION: The HIF-1α levels were decreased in all patients on postoperative days, T2 and T3, compared with the preoperative values. Our results indicated that HIF-1α may be a surrogate marker after revascularization in patients with PAD. Further studies are needed to analyze the sensitivity, specificity, and cut-off values of HIF-1α in patients with PAD.

Successful treatment of massive pulmonary embolism in a pregnant woman complicated with atypical hemolytic uremic syndrome.

The treatment of the massive pulmonary embolism concomitant hemodynamic instability in pregnancy is difficult and controversial and carries a high risk for both the baby and the mother. The catheter-directed thrombectomy with or without extracorporeal membrane oxygenation support may be a suitable management strategy in suitable cases but pregnancy-related complications may follow the treatment of pulmonary embolism and atypical hemolytic uremic syndrome should be considered in the differential diagnosis. We present a case of a 32-year-old patient who had a pulmonary embolism with shock in the 8th week of pregnancy complicated by atypical hemolytic uremic syndrome.

Endovascular stent graft repair with chimney technique of an abdominal aortic aneurysm with concomitant horseshoe kidney.

A 68-year-old male patient was referred to our clinic for treatment of an infrarenal abdominal aortic aneurysm. Computed tomography angiography revealed a horseshoe kidney overlying the aneurysm. The patient had an accessory renal artery arising from the anterior aspect of the aneurysm. Endovascular aneurysm repair was performed and the accessory renal artery could be revascularized successfully by chimney technique without any morbidity. Postoperative computed tomography angiography revealed complete exclusion of the aneurysm with no endoleak and a patent chimney graft.

Autologous Saphenous Vein Panel Graft for Vascular Reconstruction.

BACKGROUND: This study aims to present early and midterm results of vascular reconstruction with saphenous vein panel graft. METHODS: Between August 2014 and August 2017, 11 saphenous vein panel grafts were used for vascular reconstruction in 10 patients. Patient data including age, gender, etiology of the vascular pathology, concomitant injury, site of injury, surgical procedure, additional surgical procedure, and hemodynamic status were retrospectively collected and analyzed. The Kaplan-Meier method was used to calculate the reintervention and patency rates. RESULTS: Mean duration of follow-up was 16.5 ± 13.2 months (ranged, 2-39 months). The freedom from reintervention for any reason was 82% at 1 and 2 years. There was no evidence of arterial claudication or venous insufficiency in all patients. The primary patency rates were 82% at 1 and 2 years. There was no mortality, deep venous thrombosis, pulmonary embolism, graft thrombosis, anastomotic stenosis, diameter discrepancy, and aneurysm formation during late follow-up. CONCLUSIONS: The autologous saphenous panel vein graft enables the surgeon to prepare suitable conduits easily with an appropriate diameter and length for vascular reconstruction. Although long-term results are unknown, this technique provides high patency rates in midterm follow-up, resistance to infection, and low reintervention rates. In conclusion, autologous saphenous vein panel grafts may well be preferred in various vascular disorders that require surgical reconstruction.